U.S. patent application number 16/287884 was filed with the patent office on 2019-06-27 for process for producing articles formed with biodegradable materials and strength characteristics of the same.
The applicant listed for this patent is Biologiq, Inc. Invention is credited to Bradford LaPray, Wenji Quan.
Application Number | 20190194426 16/287884 |
Document ID | / |
Family ID | 57609175 |
Filed Date | 2019-06-27 |
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United States Patent
Application |
20190194426 |
Kind Code |
A1 |
LaPray; Bradford ; et
al. |
June 27, 2019 |
PROCESS FOR PRODUCING ARTICLES FORMED WITH BIODEGRADABLE MATERIALS
AND STRENGTH CHARACTERISTICS OF THE SAME
Abstract
Described herein are strength characteristics and biodegradation
of articles produced using one or more petrochemical-based polymers
and one or more carbohydrate-based polymers. A compatibilizer can
optionally be included in the article. In some cases, the article
can include a film or bag.
Inventors: |
LaPray; Bradford; (Idaho
Falls, ID) ; Quan; Wenji; (Idaho Falls, ID) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Biologiq, Inc |
Idaho Falls |
ID |
US |
|
|
Family ID: |
57609175 |
Appl. No.: |
16/287884 |
Filed: |
February 27, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14853725 |
Sep 14, 2015 |
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16287884 |
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14853780 |
Sep 14, 2015 |
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14853725 |
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15481806 |
Apr 7, 2017 |
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14853780 |
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15481823 |
Apr 7, 2017 |
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15481806 |
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14853725 |
Sep 14, 2015 |
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15481806 |
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14853780 |
Sep 14, 2015 |
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14853725 |
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15691588 |
Aug 30, 2017 |
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14853780 |
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62187231 |
Jun 30, 2015 |
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62187231 |
Jun 30, 2015 |
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62187231 |
Jun 30, 2015 |
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62440399 |
Dec 29, 2016 |
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62442432 |
Jan 4, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B32B 27/32 20130101;
B32B 2250/24 20130101; B32B 2307/732 20130101; B32B 2250/02
20130101; B32B 2250/04 20130101; B32B 2307/546 20130101; B32B
27/302 20130101; B29C 48/875 20190201; B32B 27/28 20130101; B29C
48/022 20190201; B32B 2250/05 20130101; B29C 48/08 20190201; C08L
2203/16 20130101; B32B 27/34 20130101; C08L 2205/03 20130101; B32B
27/22 20130101; B32B 27/08 20130101; B29C 48/92 20190201; B32B 9/02
20130101; C08L 23/0815 20130101; C08L 2201/06 20130101; B29C 48/83
20190201; B32B 27/18 20130101; B32B 2439/46 20130101; B29C
2948/92704 20190201; B32B 2307/7163 20130101; C08L 3/02 20130101;
B32B 9/045 20130101; C08L 3/02 20130101; C08L 23/08 20130101; C08L
51/06 20130101; C08L 23/0815 20130101; C08L 3/02 20130101; C08L
51/06 20130101 |
International
Class: |
C08L 3/02 20060101
C08L003/02; B29C 48/08 20060101 B29C048/08; B32B 9/02 20060101
B32B009/02; B32B 9/04 20060101 B32B009/04; C08L 23/08 20060101
C08L023/08; B29C 48/92 20060101 B29C048/92; B29C 48/80 20060101
B29C048/80; B29C 48/875 20060101 B29C048/875 |
Claims
1. A process comprising: providing one or more polymeric materials;
providing one or more starch-based polymeric materials formed from
a mixture of starches including a first starch and a second starch;
mixing the one or more polymeric materials and the one or more
starch-based polymeric materials to produce a mixture of materials;
heating the mixture of materials; and producing an article using
the mixture of materials, the article having a strength value that
is greater than: (i) a strength value of a first article including
the polymeric material and a first starch-based polymeric material
formed from a single starch that is the first starch, and (ii) a
second strength value of a second article including the polymeric
material and a second starch-based polymeric material formed from a
single starch that is the second starch.
2. The process of claim 1, wherein producing the article using the
mixture of materials includes extruding the mixture of materials to
produce an extruded object.
3. The process of claim 2, wherein the process further includes
injecting a gas into the extruded object, the object comprising a
film, wherein the film has a dart drop impact test value of at
least 200 g for a 1 mil thick film.
4. The process of claim 3, wherein the film has a dart drop impact
test value of at least 225 g for a 1 mil thick film.
5. The process of claim 3, wherein the film has a dart drop impact
test value from about 245 g to about 350 g for a 1 mil thick
film.
6. The process of claim 1, wherein: the mixture of materials
further comprises one or more compatibilizers; and the mixture of
materials includes: from about 10% by weight to about 40% by weight
of the one or more starch-based polymeric materials, from about 60%
by weight to about 89% by weight of the one or more polymeric
materials; and from about 1% by weight to about 9% by weight of the
one or more compatibilizers.
7. The process of claim 1, wherein the article includes a film
having a thickness from about 0.8 mil to about 2 mils.
8. The process of claim 1, wherein the polymeric material comprises
a polyolefin-based polymeric material.
9. The process of claim 1, wherein the polymeric material comprises
at least one of polyethylene, polypropylene, polystyrene, high
impact polystyrene, nylon, polymethylpentene, or polybutene.
10. The process of claim 9, wherein the polymeric material
comprises a polyethylene, the polyethylene comprising at least one
of ultra-high-molecular-weight polyethylene,
ultra-low-molecular-weight polyethylene, high-molecular-weight
polyethylene, high-density polyethylene, high-density cross-linked
polyethylene, cross-linked polyethylene, medium-density
polyethylene, linear low-density polyethylene, low-density
polyethylene, or very-low-density polyethylene.
11. The process of claim 1, wherein the heating is to a temperature
in a range from about 120.degree. C. to about 180.degree. C.
12. The process of claim 1, wherein the starch-based polymeric
material is formed from the first starch, the second starch, and
one or more plasticizers.
13. The process of claim 1, wherein the mixture of the one or more
polymeric materials and the one or more starch-based polymeric
materials further comprises a compatibilizer.
14. The process of claim 13, wherein the compatibilizer is present
in an amount of about 3% by weight to about 7% by weight of the
mixture.
15. The process of claim 1, wherein the first starch is derived
from one of potato, corn, or tapioca; and the second starch is
derived from a different one of potato, corn, or tapioca.
16. The process of claim 1, wherein the starch-based polymeric
material is present in an amount from about 20% by weight to about
30% by weight of the article and the polymeric material is a
polyolefin-based polymeric material that is present in an amount
from about 65% by weight to about 75% by weight of the article.
17. The process of claim 1, wherein the first starch comprises at
least about 50% by weight of the mixture of starches, and the
second starch comprises at least 5% by weight of the mixture of
starches.
18. The process of claim 1, wherein the second starch comprises
about 10% by weight of the mixture of starches.
19. The process of claim 1, wherein: the starch-based polymeric
material is formed from a mixture of the first starch, the second
starch and a third starch; the third starch comprises at least
about 5% by weight of the mixture of starches.
20. The process of claim 1, wherein the article has a tensile
elongation at break value in a machine direction that is greater
than a tensile elongation at break value in the machine direction
of a comparative article formed from the polymeric material alone
that is free of starch-based polymeric materials.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application
Ser. No. 14/853,725 filed on Sep. 14, 2015, entitled "Articles
Formed with Biodegradable Materials and Strength Characteristics of
Same," which application claims the benefit of, and priority to,
U.S. Provisional Patent Application No. 62/187,231 filed on Jun.
30, 2015. This application is also a continuation of U.S.
application Ser. No. 14/853,780 filed Sep. 14, 2015. This
application is also a continuation of U.S. patent application Ser.
Nos. 15/481,806 and 15/481,823, both filed Apr. 7, 2017. U.S.
application Ser. No. 15/481,806 is a continuation-in-part of U.S.
application Ser. Nos. 14/853,725 and 14/853,780, each of which
claim the benefit of U.S. Application No. 62/187,231. U.S.
application Ser. No. 15/481,806 also claims the benefit of U.S.
Application No. 62/440,399 filed Dec. 29, 2016, and U.S.
Application No. 62/442,432 filed Jan. 4, 2017. Each of the above
referenced applications is incorporated by reference in its
entirety herein.
[0002] This application also incorporates by reference and is a
continuation of U.S. application Ser. No. 15/691,588 filed Aug. 30,
2017. U.S. Provisional Patent Application No. 62/483,109, filed
Apr. 7, 2017 is also incorporated by reference herein, in its
entirety.
BACKGROUND
[0003] Traditional petrochemical-based plastics are formulated to
be strong, lightweight, and durable. However, these plastics are
typically not biodegradable, and as a result, hundreds of millions
of tons of plastic sits in landfills or floats in the ocean. In
trying to reduce the amount of plastic waste, some articles
typically produced using petrochemical-based plastics are being
produced using biodegradable materials.
SUMMARY
[0004] This disclosure is directed to articles that are formed with
biodegradable materials. In particular, the disclosure describes
strength characteristics and biodegradability of the articles
formed with the biodegradable materials. Processes to produce the
articles with biodegradable materials are also described. In some
cases, articles can be produced from a mixture of one or more
synthetic, e.g., petrochemical-based polymeric materials and one or
more carbohydrate-based polymeric materials. In a particular
example, the one or more carbohydrate-based polymeric materials can
include one or more starch-based polymeric materials. Optionally, a
compatibilizer can also be used to form the articles.
[0005] In an implementation, a process to produce an article can
include providing one or more petrochemical-based polymeric
materials and one or more carbohydrate-based polymeric materials.
The one or more petrochemical-based polymeric materials and the one
or more carbohydrate-based polymeric materials can then be mixed
and heated. The resulting mixture can be extruded into a number of
plastic products using plastics processing equipment, such as
injection molders, blow molders, thermoformers, etc., and a gas can
be injected into the extruded mixture to form a film. Optionally,
the extruded film can then be processed into a bag or another type
of article.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The detailed description is described with reference to the
accompanying figures. In the figures, the left-most digit(s) of a
reference number identifies the figure in which the reference
number first appears. The same reference numbers in different
figures generally indicates similar or identical items.
[0007] FIG. 1 illustrates a flow diagram of an example process of
forming an article including biodegradable materials.
[0008] FIG. 2 illustrates components of an example manufacturing
system to produce articles including biodegradable materials.
[0009] FIG. 3A and FIG. 3B illustrate percent biodegradation
measured over 32 days according to biomethane potential testing of
four samples formed according to techniques described herein.
[0010] FIG. 4A and FIG. 4B illustrate percent biodegradation
measured over 32 days according to biomethane potential testing of
three additional samples formed according to techniques described
herein.
[0011] FIG. 5A and FIG. 5B illustrate percent biodegradation
measured over 91 days according to biomethane potential testing of
four samples formed according to techniques described herein.
[0012] FIG. 6A and FIG. 6B illustrate percent biodegradation
measured over 91 days according to biomethane potential testing of
three additional samples formed according to techniques described
herein.
[0013] FIG. 7A and FIG. 7B illustrate percent biodegradation
measured over 71 days according to biomethane potential testing of
one sample formed according to techniques described herein.
[0014] FIG. 8A and FIG. 8B show the results of the biodegradation
portion of the ASTM D-6400 test performed according to ASTM D-5338
for a first sample and a second sample formed according to
techniques described herein.
[0015] FIG. 9A and FIG. 9B show the results of the biodegradation
portion of the ASTM D-6400 test performed according to ASTM D-5338
for a third sample and a fourth sample formed according to
techniques described herein.
[0016] FIG. 10 shows the results of the phytotoxicity portion of
the ASTM D-6400 test for a first sample formed according to
techniques described herein.
[0017] FIG. 11 shows the results of the phytotoxicity portion of
the ASTM D-6400 test for a second sample formed according to
techniques described herein.
[0018] FIG. 12 shows the results of the phytotoxicity portion of
the ASTM D-6400 test for a third sample formed according to
techniques described herein.
[0019] FIG. 13 shows the results of the phytotoxicity portion of
the ASTM D-6400 test for a fourth sample formed according to
techniques described herein.
[0020] FIG. 14A and FIG. 14B show the results of the elemental
analysis portion of the ASTM D-6400 test based on Table 3 of 40
Code of Federal Regulations (C.F.R.) Part 503.13 for a first sample
and a second sample formed according to techniques described
herein.
[0021] FIG. 15A and FIG. 15B show the results of the elemental
analysis portion of the ASTM D-6400 test based on Table 3 of 40
C.F.R. Part 503.13 for a third sample and a fourth sample formed
according to techniques described herein.
[0022] FIG. 16 shows percent biodegradation measured over 349 days
according to testing conducted under ASTM D-5511 for three samples
formed according to the present disclosure.
[0023] FIG. 17 shows percent biodegradation measured over 843 days
according to testing conducted under ASTM D-5526 for potato bags
made with 25% ESR, 70% LLDPE, and 5% compatibilizer under simulated
landfill conditions.
[0024] FIG. 18 shows percent biodegradation measured over 370 days
according to testing conducted under ASTM D-5338 for various
samples made according to the present disclosure, as well as
comparative controls.
[0025] FIG. 19 shows percent biodegradation measured over 205 days
according to ASTM D-6691, meant to simulate marine conditions, for
various samples made according to the present disclosure, as well
as comparative controls.
[0026] FIG. 20 shows elastic modulus and elongation at break data
for various petrochemical plastics that are typically neither
biodegradable nor compostable (labeled standard plastics) as well
as various plastics that are biodegradable and/or compostable
(labeled biodegradable plastics).
[0027] FIG. 21 shows X-ray diffraction patterns for an exemplary
"ESR" carbohydrate-based polymeric material commercially available
from BiologiQ as compared to that of the blend of native corn
starch and native potato starch used to form the carbohydrate-based
polymeric material.
[0028] FIG. 22 shows dart strength for different thickness films
based on percentage of carbohydrate-based polymeric material in the
film.
[0029] FIG. 23 shows dart strength for different thickness films
(from about 0.1 mil up to 2 mils) formed from a blend of 25%
carbohydrate-based polymeric material, about 5% compatibilizer, and
about 70% LLDPE, as compared to 100% LLDPE film, and also showing
comparison for produce bags, haul out bags, and potato bags.
[0030] FIG. 24 shows dart strength for different thickness films
for various blended films according to the present invention, as
well as comparative films formed from virgin or recycled
materials.
DETAILED DESCRIPTION
I. Definitions
[0031] All publications, patents and patent applications cited
herein, whether supra or infra, are hereby incorporated by
reference in their entirety to the same extent as if each
individual publication, patent or patent application was
specifically and individually indicated to be incorporated by
reference.
[0032] The term "comprising" which is synonymous with "including,"
"containing," or "characterized by," is inclusive or open-ended and
does not exclude additional, unrecited elements or method
steps.
[0033] The term "consisting essentially of" limits the scope of a
claim to the specified materials or steps "and those that do not
materially affect the basic and novel characteristic(s)" of the
claimed invention.
[0034] The term "consisting of" as used herein, excludes any
element, step, or ingredient not specified in the claim.
[0035] The terms "a," "an," "the" and similar referents used in the
context of describing the inventive features (especially in the
context of the following claims) are to be construed to cover both
the singular and the plural, unless otherwise indicated herein or
clearly contradicted by context. Thus, for example, reference to a
"starch" can include one, two or more starches.
[0036] "Film," as used herein, refers to a thin continuous article
that includes one or more polymeric materials that can be used to
separate areas or volumes, to hold items, to act as a barrier,
and/or as a printable surface.
[0037] "Bag," as used herein, refers to a container made of a
relatively thin, flexible film that can be used for containing
and/or transporting goods.
[0038] "Bottle," as used herein, refers to a container that can be
made from the presently disclosed plastics, typically of a
thickness greater than a film, and which typically includes a
relatively narrow neck adjacent an opening. Such bottles may be
used to hold a wide variety of products (e.g., beverages, personal
care products such as shampoo, conditioner, lotion, soap, cleaners,
and the like).
[0039] Unless otherwise stated, all percentages, ratios, parts, and
amounts used and described herein are by weight.
[0040] Numbers, percentages, ratios, or other values stated herein
may include that value, and also other values that are about or
approximately the stated value, as would be appreciated by one of
ordinary skill in the art. A stated value should therefore be
interpreted broadly enough to encompass values that are at least
close enough to the stated value to perform a desired function or
achieve a desired result, and/or values that round to the stated
value. The stated values include at least the variation to be
expected in a typical manufacturing process, and may include values
that are within 25%, 15%, 10%, within 5%, within 1%, etc. of a
stated value. Furthermore, the terms "substantially", "similarly",
"about" or "approximately" as used herein represent an amount or
state close to the stated amount or state that still performs a
desired function or achieves a desired result. For example, the
term "substantially" "about" or "approximately" may refer to an
amount that is within 25% of, within 15% of, within 10% of, within
5% of, or within 1% of, a stated amount or value.
[0041] Some ranges are disclosed herein. Additional ranges may be
defined between any values disclosed herein as being exemplary of a
particular parameter. All such ranges are contemplated and within
the scope of the present disclosure. Further, recitation of ranges
of values herein is intended to serve as a shorthand method of
referring individually to each separate value falling within the
range. Unless otherwise indicated herein, each individual value is
incorporated into the specification as if it were individually
recited herein.
[0042] All numbers expressing quantities of ingredients,
constituents, conditions, and so forth used in the specification
and claims are to be understood as being modified in all instances
by the term "about". Notwithstanding that the numerical ranges and
parameters setting forth the broad scope of the invention are
approximations, the numerical values set forth in the specific
examples are reported as precisely as possible. Any numerical
value, however, inherently contains certain errors necessarily
resulting from the standard deviation found in their respective
testing measurements.
[0043] The phrase `free of` or similar phrases as used herein means
that the composition comprises 0% of the stated component, that is,
the component has not been intentionally added to the composition.
However, it will be appreciated that such components may
incidentally form under appropriate circumstances, may be
incidentally present within another included component, e.g., as an
incidental contaminant, or the like.
[0044] The phrase "substantially free of" or similar phrases as
used herein means that the composition preferably comprises 0% of
the stated component, although it will be appreciated that very
small concentrations may possibly be present, e.g., through
incidental formation, incidental contamination, or even by
intentional addition. Such components may be present, if at all, in
amounts of less than 1%, less than 0.5%, less than 0.25%, less than
0.1%, less than 0.05%, less than 0.01%, less than 0.005%, or less
than 0.001%.
[0045] All methods described herein can be performed in any
suitable order unless otherwise indicated herein or otherwise
clearly contradicted by context. The use of any and all examples,
or example language (e.g., "such as") provided herein is intended
merely to better illuminate the inventive features and does not
pose a limitation on the scope of the inventive features otherwise
claimed. No language in the specification should be construed as
indicating any non-claimed element essential to the practice of the
inventive features.
[0046] The particulars shown herein are by way of example and for
purposes of illustrative discussion of the preferred embodiments of
the inventive features and are presented in the cause of providing
what is believed to be the most useful and readily understood
description of the principles and conceptual aspects of various
embodiments of the inventive features. In this regard, no attempt
is made to show structural details of the inventive features in
more detail than is necessary for the fundamental understanding of
the inventive features, the description taken with the drawings
and/or examples making apparent to those skilled in the art how the
several forms of the inventive features may be embodied in
practice.
[0047] Definitions and explanations used in the present disclosure
are meant and intended to be controlling in any future construction
unless clearly and unambiguously modified in the examples or when
application of the meaning renders any construction meaningless or
essentially meaningless. In cases where the construction of the
term would render it meaningless or essentially meaningless, the
definition should be taken from Webster's Dictionary, 3rd Edition
or a dictionary known to those of ordinary skill in the art.
II. Introduction
[0048] The present disclosure is directed to, among other things,
articles that are formed from biodegradable materials, as well as
systems and processes to produce such articles. Generally, the
articles of the present disclosure include one or more
carbohydrate-based polymeric materials. The articles can also be
produced using a mixture of one or more carbohydrate-based
polymeric materials and one or more petrochemical-based polymeric
materials. In an implementation, articles can be formed by mixing
one or more carbohydrate-based polymeric materials and one or more
petrochemical-based polymeric materials, heating the mixture, and
extruding the mixture. In various embodiments, the
carbohydrate-based polymeric materials can include starch-based
polymeric materials.
[0049] The articles described herein can be produced in the form of
films, bags, and the like which are made using blown film equipment
along with other articles that are produced using injection
molding, blow molding, thermoforming, and other plastic
manufacturing processes.
[0050] Examples of suitable carbohydrate-based or starch-based
polymeric materials for use in forming such articles are available
from BiologiQ, under the tradename ESR ("Eco Starch Resin").
Specific examples include, but are not limited to GS-270, GS-300,
and GS-330. Specific characteristics of such ESR materials will be
described in further detail herein. Other carbohydrate-based or
starch-based polymeric materials exhibiting similar properties may
also be suitable for use, such that ESR available from BiologiQ is
merely a non-limiting example of a suitable carbohydrate-based or
starch based polymeric material.
III. Exemplary Articles and Methods
[0051] The techniques and processes described herein can be
implemented in a number of ways. Example implementations are
provided below with reference to the following figures.
[0052] FIG. 1 illustrates an example process 100 of manufacturing
an article including biodegradable materials. At 102, the process
100 can include providing one or more petrochemical-based polymeric
materials. In addition, at 104, the process 100 can include
providing one or more carbohydrate-based polymeric materials. In
some cases, the one or more carbohydrate-based polymeric materials
can include one or more starch-based polymeric materials. The one
or more carbohydrate-based polymeric materials and the one or more
petrochemical-based polymeric materials can be provided in a
particular form, such as pellets, powders, nurdles, slurry, and/or
liquids. In specific embodiments, pellets can be used.
[0053] In addition, providing the one or more petrochemical-based
polymeric materials and the one or more carbohydrate-based
polymeric materials can include feeding the one or more
petrochemical-based polymeric materials and the one or more
carbohydrate-based polymeric materials into an extruder. For
example, the one or more carbohydrate-based polymeric materials and
the one or more petrochemical-based polymeric materials can be fed
into one or more hoppers of an extruder. In some cases, the one or
more carbohydrate-based polymeric materials and the one or more
petrochemical-based polymeric materials can be fed into the
extruder at approximately the same time. In other situations, the
one or more carbohydrate-based polymeric materials and the one or
more petrochemical-based polymeric materials can be fed into the
extruder at different times. Furthermore, the one or more
carbohydrate-based polymeric materials and the one or more
petrochemical-based polymeric materials can be fed into a chamber
of the extruder. In an implementation, the one or more
carbohydrate-based polymeric materials and the one or more
petrochemical-based polymeric materials can be fed into the same
chamber of the extruder. In another implementation, the one or more
carbohydrate-based polymeric materials and the one or more
petrochemical-based polymeric materials can be fed into different
chambers of the extruder.
[0054] In some cases, the petrochemical-based polymeric materials
can include polyolefins. For example, the petrochemical-based
polymeric materials can include, but are not limited to, a
polyethylene (PE), a polypropylene (PP), a polystyrene (PS), a high
impact polystyrene (HIPS), a nylon, a polymethylpentene, a
polybutene, polybutyrate adipate terephthalate (PBAT), other
polyolefins, or combinations thereof. It will be apparent to those
of skill in the art that a wide variety of petrochemical-based or
other synthetic polymeric materials may be used. In various
embodiments, the petrochemical based polymeric materials can
include an ultra-high-molecular-weight polyethylene (UHMWPE), an
ultra-low-molecular-weight polyethylene (ULMWPE), a
high-molecular-weight polyethylene (HMWPE), a high-density
polyethylene (HDPE), a high-density cross-linked polyethylene
(HDXLPE), a cross-linked polyethylene (PEX or XLPE), a
medium-density polyethylene (MDPE), a linear low-density
polyethylene (LLDPE), a low-density polyethylene (LDPE), or a
very-low-density polyethylene (VLDPE). In specific embodiments, the
petrochemical-based polymeric materials can include a LLDPE. In
some cases, a LLDPE can be formed using a metallocene catalyst.
[0055] The one or more carbohydrate-based polymeric materials can
be formed from a plurality of materials (e.g., a mixture) including
one or more starches. For example, the one or more starches can be
produced from one or more plants, such as corn starch, tapioca
starch, cassava starch, wheat starch, potato starch, rice starch,
sorghum starch, and the like. In various embodiments, the
starch-based polymers can be formed from a mixture of starches
derived from two or more plants, three or more plants, or four or
more plants. In some cases, the materials from which the one or
more carbohydrate-based polymeric materials are formed can also
include a plasticizer. An amount of water can be present in the
finished one or more carbohydrate-based polymeric materials.
[0056] In an implementation, the one or more carbohydrate-based
polymeric materials can be formed from a plurality of materials
including at least about 65% by weight of one or more starches, at
least about 70% by weight of one or more starches, at least about
75% by weight of one or more starches, or at least about 80% by
weight of one or more starches. In addition, the materials from
which the one or more carbohydrate-based polymeric materials are
formed can include no greater than about 99% by weight of one or
more starches, no greater than about 95% by weight of one or more
starches, no greater than about 90% by weight of one or more
starches, or no greater than about 85% by weight of one or more
starches. In an illustrative example, the materials from which the
one or more carbohydrate-based polymeric materials are formed can
include from about 60% by weight to about 99% by weight of one or
more starches. In another illustrative example, the materials from
which the one or more carbohydrate-based polymeric materials are
formed can include from about 65% by weight to about 80% by weight
of one or more starches. In another implementation, such
percentages may represent that fraction of the finished
carbohydrate-based polymeric material that is derived from starch
(e.g., at least about 65% of the carbohydrate based polymeric
material may be attributed to (formed from) starch as the starting
material).
[0057] Mixtures of starches may be used in forming the
carbohydrate-based polymeric material. In some embodiments, a
starch can be present in a mixture of starches at an amount of at
least about 1% by weight, of at least about 2% by weight, of at
least about 3% by weight, of at least about 4% by weight, of at
least about 5% by weight, at least about 10% by weight, at least
about 15% by weight, at least about 20% by weight, at least about
25% by weight, at least about 30% by weight, at least about 35% by
weight, or at least about 40% by weight relative to the combined
weight of the plurality of starches. In addition, a starch can be
present in a mixture of starches at an amount no greater than about
95% by weight, no greater than about 90% by weight, no greater than
about 85% by weight, no greater than about 80% by weight, no
greater than about 75% by weight, no greater than about 70% by
weight, no greater than about 65% by weight, no greater than about
60% by weight, no greater than about 55% by weight, or no greater
than about 50% by weight. In some embodiments, a starch can be
present in a mixture of starches in an amount from about 20% by
weight to about 25% by weight, from about 30% by weight to about
35% by weight, from about 45% by weight to about 55% by weight, or
from about 70% by weight to about 80% by weight.
[0058] In an implementation, the one or more carbohydrate-based
polymeric materials can be formed from a plurality of materials
including a mixture of a first starch and a second starch. In these
cases, the starch materials or materials as a whole from which the
carbohydrate-based polymeric material is formed can include at
least about 50% by weight of the first starch, at least about 55%
by weight of the first starch, at least about 60% by weight of the
first starch, at least about 65% by weight of the first starch, or
at least about 70% by weight of the first starch. Additionally, the
materials can include no greater than about 95% by weight of the
first starch, no greater than about 90% by weight of the first
starch, no greater than about 85% by weight of the first starch, no
greater than about 80% by weight of the first starch, or no greater
than about 75% by weight of the first starch. In an illustrative
example, the materials can include from about 50% by weight to
about 98% by weight of the first starch. In another illustrative
example, the materials can include from about 55% by weight to
about 85% by weight of the first starch. In an additional
illustrative example, the materials can include from about 55% by
weight to about 70% by weight of the first starch. In a further
illustrative example, the materials can include from about 75% by
weight to about 90% by weight of the first starch. Also, the
materials can include from about 65% by weight to about 75% by
weight of the first starch. In another implementation, such
percentages may represent that fraction of the finished
carbohydrate-based polymeric material that is derived from or
attributable to the first starch (e.g., at least about 50% of the
carbohydrate based polymeric material may be attributed to (formed
from) the first starch as a starting material).
[0059] With regard to a second starch where the carbohydrate-based
material is formed from two or more starches, the starch materials,
or the materials as a whole can include at least about 1% by weight
of the second starch, at least about 2% by weight of the second
starch, at least about 3% by weight of the second starch, at least
about 4% by weight of the second starch, at least about 5% by
weight of the second starch, at least about 10% by weight of the
second starch, at least about 15% by weight of the second starch,
at least about 20% by weight of the second starch, or at least
about 25% by weight of the second starch. Additionally, the starch
materials or materials as a whole can include no greater than about
50% by weight of the second starch, no greater than about 45% by
weight of the second starch, no greater than about 40% by weight of
the second starch, no greater than about 35% by weight of the
second starch, or no greater than about 30% by weight of the second
starch. In an illustrative example, the starch materials or
materials as a whole can include from about 2% by weight to about
50% by weight of the second starch. In another illustrative
example, the starch materials or materials as a whole can include
from about 10% by weight to about 45% by weight of the second
starch. In an additional illustrative example, the starch materials
or materials as a whole can include from about 15% by weight to
about 25% by weight of the second starch. In a further illustrative
example, the starch materials or materials as a whole can include
from about 35% by weight to about 45% by weight of the second
starch. Also, the starch materials or materials as a whole can
include from about 25% by weight to about 35% by weight of the
second starch. In another implementation, such percentages may
represent that fraction of the finished carbohydrate-based
polymeric material that is derived from or attributable to the
second starch (e.g., no greater than about 50% of the carbohydrate
based polymeric material may be attributed to (formed from) the
second starch as a starting material).
[0060] In some implementations, the one or more carbohydrate-based
polymeric materials can be formed from a mixture of a first starch,
a second starch, and a third starch. For example, the starch
materials or materials as a whole can include at least about 30% by
weight of the first starch, at least about 35% by weight of the
first starch, at least about 45% by weight of the first starch, at
least about 50% by weight of the first starch, or at least about
55% by weight of the first starch. In addition, the starch
materials or materials as a whole can include no greater than about
80% by weight of the first starch, no greater than about 75% by
weight of the first starch, no greater than about 70% by weight of
the first starch, no greater than about 65% by weight of the first
starch, or no greater than about 60% by weight of the first starch.
In an illustrative example, the starch materials or materials as a
whole can include from about 30% by weight to about 80% by weight
of the first starch. In another illustrative example, the starch
materials or materials as a whole can include from about 30% by
weight to about 40% by weight of the first starch. In an additional
illustrative example, the starch materials or materials as a whole
can include from about 45% by weight to about 55% by weight of the
first starch. In a further illustrative example, the starch
materials or materials as a whole can include from about 55% by
weight to about 65% by weight of the first starch. In another
implementation, such percentages may represent that fraction of the
finished carbohydrate-based polymeric material that is derived from
or attributable to the first starch (e.g., at least about 30% of
the carbohydrate based polymeric material may be attributed to
(formed from) the first starch as a starting material).
[0061] Additionally, in a carbohydrate-based polymeric material
formed from a mixture of a first starch, a second starch, and a
third starch, the starch materials or materials as a whole used in
making the carbohydrate-based polymeric material can include at
least about 1% by weight of the second starch, at least about 2% by
weight of the second starch, at least about 3% by weight of the
second starch, at least about 4% by weight of the second starch at
least about 5% by weight of the second starch, at least about 10%
by weight of the second starch, at least about 15% by weight of the
second starch, or at least about 20% by weight of the second
starch. In an implementation, the starch materials or materials as
a whole can include no greater than about 40% by weight of the
second starch, no greater than about 35% by weight of the second
starch, no greater than about 30% by weight of the second starch,
or no greater than about 25% by weight of the second starch. In an
illustrative example, the starch materials or materials as a whole
can include from about 5% by weight to about 40% by weight of the
second starch. In another illustrative example, the starch
materials or materials as a whole can include from about 15% by
weight to about 25% by weight of the second starch. In an
additional illustrative example, the starch materials or materials
as a whole can include from about 27% by weight to about 38% by
weight of the second starch. In another implementation, such
percentages may represent that fraction of the finished
carbohydrate-based polymeric material that is derived from or
attributable to the second starch (e.g., at least about 5% of the
carbohydrate based polymeric material may be attributed to (formed
from) the second starch as a starting material).
[0062] Further, when the materials from which the
carbohydrate-based polymeric material is formed include a mixture
of a first starch, a second starch, and a third starch, the starch
materials or materials as a whole can include at least about 1% by
weight of the third starch, at least about 2% by weight of the
third starch, at least about 3% by weight of the third starch, at
least about 4% by weight of the third starch, at least about 5% by
weight of the third starch, at least about 10% by weight of the
third starch, at least about 15% by weight of the third starch, or
at least about 20% by weight of the third starch. In an
implementation, the starch materials or materials as a whole can
include no greater than about 40% by weight of the third starch, to
greater than about 35% by weight of the third starch, no greater
than about 30% by weight of the third starch, or no greater than
about 25% by weight of the third starch. In an illustrative
example, the starch materials or materials as a whole can include
from about 5% by weight to about 40% by weight of the third starch.
In another illustrative example, the starch materials or materials
as a whole can include from about 15% by weight to about 25% by
weight of the third starch. In an additional illustrative example,
the starch materials or materials as a whole can include from about
27% by weight to about 38% by weight of the third starch. In
another implementation, such percentages may represent that
fraction of the finished carbohydrate-based polymeric material that
is derived from or attributable to the third starch (e.g., at least
about 5% of the carbohydrate based polymeric material may be
attributed to (formed from) the third starch as a starting
material).
[0063] A plasticizer used in forming the one or more
carbohydrate-based polymeric materials can include polyethylene
glycol, sorbitol, glycerin, polyhydric alcohol plasticizers,
hydrogen bond forming organic compounds which do not have a
hydroxyl group, anhydrides of sugar alcohols, animal proteins,
vegetable proteins, aliphatic acids, phthalate esters, dimethyl and
diethylsuccinate and related esters, glycerol triacetate, glycerol
mono and diacetates, glycerol mono, di, and tripropionates,
butanoates, tearates, lactic acid esters, citric acid esters,
adipic acid esters, stearic acid esters, oleic acid esters, other
acid esters, or combinations thereof. In specific implementations,
the plasticizer can include glycerin.
[0064] In an implementation, the materials from which the one or
more carbohydrate-based polymeric materials are formed can include
at least about 12% by weight of a plasticizer, at least about 15%
by weight of a plasticizer, at least about 18% by weight of a
plasticizer, at least about 20% by weight of a plasticizer, or at
least about 22% by weight of a plasticizer. Additionally, the
materials can include no greater than about 35% by weight of a
plasticizer, no greater than about 32% by weight of a plasticizer,
no greater than about 30% by weight of a plasticizer, no greater
than about 28% by weight of a plasticizer, or no greater than about
25% by weight of a plasticizer. In an illustrative example, the
materials can include from about 12% by weight to about 35% by
weight of a plasticizer. In another illustrative example, the
materials can include from about 15% by weight to about 30% by
weight of a plasticizer. In an additional illustrative example, the
materials can include from about 18% by weight to about 28% by
weight of a plasticizer. In another implementation, such
percentages may represent that fraction of the finished
carbohydrate-based polymeric material that is derived from or
attributable to the plasticizer (e.g., at least about 12% of the
carbohydrate based polymeric material may be attributed to (formed
from) the plasticizer as a starting material).
[0065] In some cases, the finished one or more carbohydrate-based
polymeric materials include no greater than about 5% by weight
water, no greater than about 4% by weight water, no greater than
about 3% by weight water, no greater than about 2% by weight water,
no greater than about 1.5% by weight water, no greater than about
1.4% water, no greater than about 1.3% water, no greater than about
1.2% water, no greater than about 1.1% water or no greater than
about 1% by weight water. Additionally, the finished one or more
carbohydrate-based polymeric materials can include at least about
0.1% by weight water, at least about 0.3% by weight water, at least
about 0.6% by weight water, or at least about 0.8% by weight water.
In an illustrative example, the finished one or more
carbohydrate-based polymeric materials include from about 0.1% by
weight to about 5% by weight water. In another illustrative
example, the finished one or more carbohydrate-based polymeric
materials include from about 0.4% by weight to about 2% by weight
water. In an additional illustrative example, the finished one or
more carbohydrate-based polymeric materials can include from about
0.5% by weight to about 1.5% by weight water. The ESR materials
available from BiologiQ are examples of such finished
carbohydrate-based polymeric materials, although it will be
appreciated that other materials available elsewhere (e.g., at some
future time) may also be suitable for use.
[0066] Examples of suitable carbohydrate-based (e.g., starch-based)
polymeric materials for use in forming films and other articles are
available from BiologiQ, located in Idaho Falls, Id., under the
tradename ESR ("Eco Starch Resin"). Specific examples include, but
are not limited to GS-270, GS-300, and GS-330. Fractions of starch,
and glycerin or other plasticizers used in forming ESR are
described in detail above. ESR may be provided in pellet form.
Physical characteristics for GS-270 and GS-300 are shown in Table 1
below. GS-270 is formed from about 27% glycerin, with substantially
the balance of the finished product being formed from or
attributable to one or more starches as starting materials. GS-300
is formed from about 30% glycerin, with substantially the balance
of the finished product being formed from or attributable to one or
more starches as starting materials.
TABLE-US-00001 TABLE 1 GS-270 GS-300 TEST NOMINAL NOMINAL PROPERTY
METHOD VALUE VALUE Density ASTM D-792 1.40 g/cm.sup.3 1.42
g/cm.sup.3 THERMAL PROPERTIES Melt Flow Index ASTM D-1238 1.98 g/10
min 1.95 g/10 min 200.degree. C./5 kg Melting Temp. ASTM D-3418
166-180.degree. C. 166-180.degree. C. Range Glass Transition ASTM
D-3418 81-100.degree. C. 81-100.degree. C. Temp. MECHANICAL
PROPERTIES Tensile ASTM D-638 >30 MPa >14 MPa Strength @
Yield Tensile ASTM D-638 >30 MPa >14 MPa Strength @ Break
Young's Modulus ASTM D-638 1.5 GPa 1.5 GPa Elongation at ASTM D-638
<10% <10% Break Impact Resistance ASTM D-5628 3.5 kg 4.5 kg
(Dart) ADDITIONAL PROPERTIES Water Content ASTM D-6980
.ltoreq.1.5%, or .ltoreq.1% .ltoreq.1.5%, or .ltoreq.1%
[0067] The above characteristics shown for GS-270 and GS-300 are
exemplary of other ESR products available from BiologiQ, although
values may vary somewhat. For example, ESR products from BiologiQ
may generally have a glass transition temperature ranging from
about 70.degree. C. to about 100.degree. C. Those of skill in the
art will appreciate that glass transition temperature can be
indicative of degree of crystallinity. Values for melting
temperature range, density, Young's Modulus, and water content may
be identical or similar to those shown above in Table 1. Some
characteristics may similarly vary somewhat (e.g., +25%, or +10%)
from values shown for GS-270 and GS-300. ESR has an amorphous
structure (e.g., more amorphous than typical raw starch). For
example, typical raw starch powder has a mostly crystalline
structure (e.g., greater than 50%), while ESR has a mostly
amorphous structure (e.g., less than 10% crystalline). ESR has a
low water content, as described. As ESR absorbs moisture, it
exhibits plastic behavior and becomes flexible. When removed from a
humid environment, the material dries out and becomes stiff again
(e.g., again exhibiting less than about 1% water content). The
moisture present in ESR (e.g., in pellet form) may be released in
the form of steam during processing such as that shown in FIG. 1.
As a result, films or other articles produced from a starch-based
polymeric material such as ESR and a petrochemical-based polymeric
material (e.g., a polyolefin such as polyethylene) may exhibit even
lower water content (e.g., negligible), as the water in the ESR may
typically be released during formation of the film or other
article.
[0068] Such low water content in the carbohydrate-based polymeric
material can be important, as significant water content results in
incompatibility with the petro-chemical-based polymeric material
when attempting to form a thin film, as the water vaporizes,
resulting in voids within the film, as well as other problems. For
example, when blowing a film, the carbohydrate-based polymeric
material used may have less than 1.5% water, and preferably no more
than 1.1% water (e.g., less than about 1% water).
[0069] Low water content is not achieved in the ESR material
through esterification, as is common in some conventional TPS
materials that may include relatively low water content. Such
esterification can be expensive and complex to perform.
Furthermore, the ESR materials that are exemplary of the
carbohydrate-based polymeric materials employable herein also
typically do not themselves actually include any identifiable
starch, or identifiable glycerin, as such, as the starting
materials of the ESR or other carbohydrate-based polymeric material
have been chemically reacted and/or altered. X-ray diffraction
patterns of exemplary carbohydrate-based polymeric materials as
described below (e.g., and shown in FIG. 21) evidence such chemical
alteration, showing that the finished polymeric material may be
substantially devoid of starch in such identifiable, native form.
In other words, the carbohydrate-based polymeric material is not
simply recognized as a mixture including starch and glycerin. The
low water content achievable in the carbohydrate-based polymeric
material is believed to be due at least in part to the chemical
alteration of the starch and plasticizer materials into a
thermoplastic polymer, which does not retain water as would native
starch, or conventional thermoplastic starches.
[0070] Processing at relatively high temperatures may result in
some release of volatized glycerin (e.g., visible as smoke). Drying
of pellets can be performed by introducing warm dry air, e.g., at
60.degree. C. for 1-4 hours. Pellets should be dried to less than
about 1% moisture content prior to processing. ESR pellets may
simply be stored in a sealed container with a desiccant in a dry
location, away from heat.
[0071] In addition to ESR being thermoplastic, the ESR may also be
thixotropic, meaning that the material is solid at ambient
temperature, but flows as a liquid when heat, pressure and/or
frictional movement are applied. Advantageously, pellets of ESR can
be used the same as petrochemical based pellets in standard plastic
production processes. ESR materials and products made therefrom may
exhibit gas barrier characteristics. Products (e.g., films) made
using such ESR pellets exhibit oxygen gas barrier characteristics
(e.g., see Example 5 for specific exemplary results). ESR materials
may be non-toxic and edible, made using raw materials that are all
edible. ESR and products made therefrom may be water resistant. For
example, ESR may resist swelling under moist heated conditions to
the point that it may not completely dissolve in boiling water
within 5 minutes. ESR may be stable, in that it may not exhibit any
significant retrogradation, even if left in relatively high
humidity conditions, which characteristic differs from many other
thermoplastic starch materials. Of course, products made with ESR
may also exhibit such characteristics. If ESR is stored in such
humid conditions, the excess absorbed water can simply be
evaporated away, and once the water content is no more than about
1%, it can be used in forming a film or other article.
[0072] The ESR material also does not typically undergo
biodegradation under typical storage conditions, even in relatively
humid conditions, as the other conditions typical of a landfill,
compost or similar disposal environment containing the particular
needed microorganisms are not present. Of course, where such
conditions are present, not only does the ESR biodegrade, but
otherwise non-biodegradable plastic materials blended therewith
surprisingly also biodegrade. Evidence of such surprising results
is included in the Examples section, included herein.
[0073] ESR can be cost competitive, being manufactured at a cost
that is competitive with traditional polyethylene plastic resins.
ESR can be mixed with other (e.g., petrochemical) polymers,
including, but not limited to PBAT, PBS, PLA, PP, PE, and/or PS. It
will be appreciated that some such polymers that ESR can be blended
with may already be biodegradable and/or compostable (e.g.,
polylactic acid (PLA), poly(butylene adipate-co-terephthalate)
(PBAT), polybutylene succinate (PBS), polycaprolactone (PCL), and
polyhydroxyalkanoates (PHA)).
[0074] ESR includes very low water content. For example, although
raw starch (e.g., used in forming ESR) may typically include about
13% water by weight, the finished ESR pellets available from
BiologiQ include less than about 1% water. ESR materials are
biodegradable, and as described herein, not only is the
starch-based ESR material biodegradable, but when blended with
other polymers, such as polyethylene, which are not biodegradable,
the blended material is also substantially entirely biodegradable.
Such results are quite surprising, and particularly advantageous.
The Examples herein evidence such surprising results. Other typical
thermoplastic starch materials do not claim or exhibit such
characteristics when blended with other polymers.
[0075] The ESR material may exhibit some elasticity, although its
elasticity may be less than many other polymers (e.g., particularly
petrochemical-based polymers). Of course, films and other articles
may be formed from blends of ESR and any desired
petrochemical-based polymer(s), providing elasticity results that
may be expected to be break and elastic modulus values for various
standard plastic ("SP") materials, various "green" renewable
plastic materials, and ESR, for comparison. The ESR in Table 2 had
a tensile strength of 40 MPa.
TABLE-US-00002 TABLE 2 COMPOSTABLE, BIODEGRADABLE OR ELONGATION
ELASTIC MATERIAL STANDARD PLASTIC AT BREAK MODULUS EcoFlex BP 700%
0.10 GPa C1200 ESR BP 100% 1.5 GPa HDPE SP 650% 0.80 GPa LDPE SP
550% 0.40 GPa PBS BP 450% 0.50 GPa PCL BP 600% 0.20 GPa PHA BP 300%
3.40 GPa PLA CP 150% 3.50 GPa PET SP 200% 2.50 GPa PP SP 500 1.75
GPa ABS SP 25 2.00 GPa Nylon SP 100 3.00 GPa
[0076] FIG. 20 shows similar data as in Table 2, in chart form. PLA
is compostable, meaning that it can degrade under elevated
temperature conditions (i.e., composting conditions), but is
technically not "biodegradable". Some of the above listed
materials, such as PBS, PCL, and PHA may be both biodegradable and
compostable. EcoFLEX.TM. is certified as compostable. FTC Green
guidelines stipulate that a plastic cannot make an unqualified
claim that it is "degradable" unless it will degrade within a
"reasonably short period of time" (most recently defined as within
5 years) "after customary disposal".
[0077] In some embodiments, the ESR could be provided in a
masterbatch formulation that may include the carbohydrate-based
polymeric material as described above, and an amount of one or more
compatibilizers. The masterbatch may also include one or more
non-biodegradable plastic materials. Such masterbatch formulation
pellets could be mixed with pellets of the non-biodegradable
plastic material at the time of processing. Any conceivable ratios
may be used in mixing such different pellets, depending on the
desired percentage of ESR and/or compatibilizer and/or conventional
non-biodegradable plastic material in the finished article.
[0078] ESR includes very low water content. For example, although
raw starch (e.g., used in forming ESR) may typically include about
13% water by weight, the finished ESR pellets available from
BiologiQ include less than about 1% water. ESR materials are
biodegradable, and as described herein, not only is the
starch-based ESR material biodegradable, but when blended with
other polymers, such as non-biodegradable PE, PP, PET, polyester,
polystyrene, ABS, polyvinyl chloride, nylon, and other
non-biodegradable plastic materials, the blended material becomes
substantially entirely biodegradable. Such results are quite
surprising, and particularly advantageous. The Examples herein
provide evidence of such surprising results. Typical thermoplastic
starch materials do not claim to or exhibit such characteristics
when blended with other plastic materials.
[0079] The ESR materials described as suitable for use herein as
the carbohydrate-based (e.g., starch-based) polymeric material are
substantially amorphous. For example, raw starch powder (e.g., such
as is used in making ESR and various other thermoplastic starch
materials) has approximately a 50% crystalline structure. ESR
materials available from BiologiQ differ from many other
commercially available thermoplastic starch (TPS) materials in
crystallinity versus amorphous characteristics. For example, p.
62-63 of "Thermoplastic Starch Composites and Blends" a PhD thesis
by Kris Frost (September 2010) states "[o]f particular interest in
TPS is completeness of gelatinisation during processing, and any
subsequent tendency toward retrogradation to form V-type amylose
crystals". Frost further continues "[g]elatinisation involves loss
of granular and crystalline structures by heating with water and
often including other plasticizers or modifying polymers.
Retrogradation is due to the re-coiling of amylose helical coils.
Starch molecules disrupted during gelatinisation slowly re-coil
into their native helical arrangements or new single helical
conformations known as V type, causing TPS films to rapidly become
brittle and lose optical clarity". Thus, conventional TPS tends to
re-form a crystalline structure after the gelatinization process
used to produce the TPS from raw starch. On the contrary, the ESR
material available from BiologiQ does not revert back to a
crystalline structure and does not become brittle. It remains
flexible. In addition, it can maintain a stable, high degree of
optical clarity, so as to be useful in forming relatively optically
clear films (e.g., particularly by sandwiching ESR between
polyethylene or other polyolefin layers).
[0080] In contrast to typical TPS materials, the ESR materials that
are suitable examples of starch-based polymeric materials for use
in forming articles described in the present application have an
amorphous microstructure, and physical characteristics as shown in
Table 1. The difference in the molecular structure between
conventional TPS and ESR materials is evidenced by the ESR
materials as described herein being much less crystalline than
conventional thermoplastic starch-based materials as shown by X-ray
diffraction, shown in FIG. 21, comparing diffraction pattern
results for ESR material available from BiologiQ (sample 1) as
compared to a blend of native raw corn starch and native raw potato
starch, from which the ESR in FIG. 21 was formed. The diffraction
pattern of the ESR as seen in FIG. 21 is much less crystalline
(e.g., crystallinity of less than about 10%) than that of the
native starch blend (crystallinity of about 50%). The difference in
diffraction pattern evidences that a substantial chemical change
has occurred in the material, due to processing from the native
starches into ESR. For example, while there is a prominent
diffraction peak between 20-25.degree. with the native starch, no
such peak is exhibited in the ESR. The native starch further shows
a strong peak at about 45.degree. (at an intensity of 0.5 to 0.6),
which peak is greatly reduced in the ESR (only of about 0.25 to
0.3). Across nearly the entire spectrum, the diffraction
intensities are higher for the native starches than for the ESR,
with the exception of from about 18.degree. to about 22.degree., as
shown. The elevated diffraction intensity seen across a wide
spectrum is indicative of greater crystallinity of the native
starches as compared to the ESR. Numerous other differences also
exist, as shown.
[0081] By way of example, the carbohydrate-based (e.g.,
starch-based) polymeric material used in making films according to
the present disclosure may have a crystallinity of less than about
40%, less than about 35%, less than about 30%, less than about 25%,
less than about 20%, less than about 15%, less than about 10%, less
than about 8%, less than about 6%, less than about 5%, or less than
about 3%. Any suitable test mechanism for determining crystallinity
may be used, e.g., including but not limited to FTIR analysis,
X-ray diffraction methods, and symmetrical reflection and
transmission techniques. Various suitable test methods will be
apparent to those of skill in the art.
[0082] In addition to the differences in the microstructure of the
finished ESR as compared to the starting materials, films, bottles,
sheets, disposable utensils, plates, cups, or other articles
produced from a blend including the carbohydrate-based polymeric
material are different from articles that are otherwise similar,
but formed using conventional TPS and starch powder. For example,
films formed by blending the starch-based polymeric materials such
as ESR as described herein with a petrochemical-based polymeric
material do not have "sea-island" features that are common when
blending conventional TPS materials with petrochemical-based
polymeric materials such as polyethylene. Properties of the
different films can be seen by comparing the physical properties of
films as shown in Table 11 of Example 5 below. In particular, Table
11 compares the physical properties of films made by blending
starch-based polymeric materials as contemplated herein with
polyethylene versus a conventional TPS blended with PE (Cardia
BL-F). In addition to the differences in properties seen in Table
11, films based on conventional TPS materials such as Cardia BL-F
are not biodegradable, and not compostable. As described herein,
use of the carbohydrate or starch-based polymeric materials as
described herein in forming a film with a petrochemical-based
polymeric material results in not just the carbohydrate-based or
starch-based material being biodegradable, but at least a portion
of the petrochemical-based polymeric material becoming
biodegradable, as a result of its blending with the
carbohydrate-based or starch-based polymeric materials. Such
results do not occur with typical TPS materials. Such differences
in biodegradability clearly illustrate that there are significant
structural differences in the resulting films and other articles,
as the entire composite structure (i.e., the film or other
structure) may be capable of being biodegraded, as shown by the
various examples below.
[0083] Without being bound by theory, it is believed that the
amorphous microstructure of the starch-based polymeric material
used to produce articles of the subject application at least
partially results in the characteristic that at least some of the
petrochemical-based polymeric material of the blended article
degrades in addition to the starch-based polymeric material. The
below examples provide evidence of such. The films and other
articles as described herein have biodegradation properties which
are not found in conventional articles.
[0084] For example, truly biodegradable plastics decompose into
natural elements or compounds such as carbon dioxide, methane,
water, inorganic compounds, or biomass via microbial assimilation
(e.g., the enzymatic action of microorganisms on the plastic
molecules). Biodegradation of plastics can be enabled by first
breaking down the polymer chains via either chemical or mechanical
action but may only be fully accomplished through decomposition of
the molecules by microbial assimilation.
[0085] Plastics made from petrochemical feedstocks begin life as
monomers (e.g., single small molecules that can react chemically
with other small molecules). When monomers are joined together,
they become polymers ("many parts"), known as plastics. Before
being joined together, many monomers are readily biodegradable,
although after being linked together through polymerization, the
molecules become so large and joined in such arrangements and
linkages that microbial assimilation by microorganisms is not
practical within any reasonable time frame.
[0086] Polymers are formed with both crystalline (regularly packed)
structures and amorphous (randomly arranged) structures. Many
polymers contain a high degree of crystallinity with some amorphous
regions randomly arranged and entangled throughout the polymeric
structure.
[0087] ESR materials available from BiologiQ are formed from
starting starch materials which are highly crystalline, but in
which the finished ESR plastic resin material exhibits low
crystallinity (substantially amorphous). Such starch-based polymer
materials are used as a starting material in the production of
articles, such as films, as described herein. ESR is, therefore,
plastic that is made from starch. Because of its natural,
starch-based origin and carefully controlled linkage types, the
molecules (size and links) of plastic made with ESR are highly
susceptible to biodegradation by enzymatic reactions caused from
the introduction of humidity (water) and bacteria or other
microorganisms, as evidenced by the experimental test results
included herein.
[0088] Polyolefins such as rigid forms of polyethylene and
polypropylene have a high degree of crystallinity and are made by
converting monomer molecules (usually petroleum derived) into long
chain polymers. The bonds created when connecting the monomers to
form long polymer chains are strong and difficult to break. Films
and other articles formed from such petrochemical-based polymeric
materials are not biodegradable. In addition, films and articles
including blends of conventional TPS and a petrochemical-based
polymeric material (e.g., such as Cardia BL-F) are also not
biodegradable.
[0089] The present inventors have developed a process for making
articles from a blend of a starch-based polymeric material having
low crystallinity with polyolefin-based or other polymeric
materials, such as polyethylene, that have a relatively high
crystallinity. The resulting thermoplastic blend has a higher
elastic modulus (stiffness, or strength) than polyethylene and can
be used to make plastic films that are stronger than films made
with pure polyethylene. For example, Table 11 of Example 5 shows
physical properties of films produced with a blend of a
petrochemical-based polymeric material and a starch-based polymeric
material (such as ESR) as compared to a 100% polyethylene film and
as compared to a film formed from a blend of a conventional TPS and
polyethylene (i.e., Cardia BL-F), neither of which are
biodegradable. Results from third party testing detailed in the
Examples show that films according to the present invention exhibit
biodegradation of not just the renewable content (i.e., the ESR),
but the petrochemical-based or other synthetic polymeric material
as well. Such results are particularly surprising, unexpected, and
advantageous.
[0090] Without being bound to any particular theory, it is believed
that the starch-based polymeric resins may reduce the crystallinity
of the blended products, interrupting the crystallinity of the
polyethylene in a way that allows water and bacteria to degrade the
arrangements and linkages of polyethylene molecules of the blend
along with the starch-based polymeric resin material. In other
words, the long polymer chains of polyethylene are more easily
broken by chemical and mechanical forces that exist in environments
that are rich in bacteria and microorganisms, when blended with
carbohydrate-based or starch-based materials as contemplated
herein. Subsequently, the microorganisms that exist naturally in
the environment (e.g., in a landfill) can consume the remaining
smaller molecules so that they are converted back into natural
components (such as CO.sub.2, CH.sub.4, and H.sub.2O).
[0091] Returning to FIG. 1, at 106, the process 100 includes mixing
the one or more petrochemical-based polymeric materials and the one
or more carbohydrate-based polymeric materials to produce a mixture
of materials. In some cases, the mixing of the one or more
petrochemical-based polymeric materials and the one or more
carbohydrate-based materials can be performed using one or more
mixing devices. In a particular implementation, a mechanical mixing
device can be used to mix the one or more petrochemical-based
polymeric materials and the one or more carbohydrate-based
polymeric materials. In an implementation, at least a portion of
the components of the mixture of the materials can be combined in
an apparatus, such as an extruder. In other implementations, at
least a portion of the components of the mixture of the materials
can be combined before being fed into the extruder.
[0092] In various implementations, the one or more
carbohydrate-based polymeric materials can be present in the
mixture of materials an amount of at least about 5% by weight of
the mixture of materials, at least about 10% by weight of the
mixture of materials, at least about 15% by weight of the mixture
of materials, at least about 20% by weight of the mixture of
materials, at least about 25% by weight of the mixture of
materials, at least about 30% by weight of the materials, at least
about 35% by weight of the mixture of materials, at least about 40%
by weight of the mixture of materials, or at least about 45% by
weight of the mixture of materials. In other implementations, the
one or more carbohydrate-based polymeric materials can be present
in the mixture of materials in an amount of no greater than about
99% by weight of the mixture of materials, no greater than about
95% by weight of the mixture of materials, no greater than about
90% by weight of the mixture of materials, no greater than about
80% by weight of the mixture of materials, no greater than about
70% by weight of the mixture of materials, no greater than about
60% by weight of the mixture of materials, or no greater than about
50% by weight of the mixture of materials. Additionally, the one or
more carbohydrate-based polymeric materials can be present in the
mixture of materials in an amount from about 20% by weight to about
40% by weight of the mixture of materials. In an illustrative
example, the mixture of materials can include from about 2% by
weight to about 98% by weight of the one or more carbohydrate-based
polymeric materials. In another illustrative example, the mixture
of materials can include from about 10% by weight to about 40% by
weight of the one or more carbohydrate-based polymeric materials.
In an additional illustrative example, the mixture of materials can
include from about 20% by weight to about 30% by weight of the one
or more carbohydrate-based polymeric materials. In a further
illustrative example, the mixture of materials can include from
about 50% by weight to about 80% by weight of the one or more
carbohydrate-based polymeric materials. In still another
illustrative example the mixture of materials can include from
about 40% by weight to about 60% by weight of the one or more
carbohydrate-based polymeric materials.
[0093] In some implementations, the mixture of materials can
include at least about 10% by weight of the one or more
petrochemical-based polymeric materials, at least about 15% by
weight of the one or more petrochemical-based polymeric materials,
at least about 20% by weight of the one or more petrochemical-based
polymeric materials, at least about 25% by weight of the one or
more petrochemical-based polymeric materials, at least about 30% by
weight of the one or more petrochemical-based polymeric materials,
at least about 35% by weight of the one or more petrochemical-based
polymeric materials, at least about 40% by weight of the one or
more petrochemical-based polymeric materials, at least about 45% by
weight of the one or more petrochemical-based polymeric materials,
or at least about 50% by weight of the one or more
petrochemical-based polymeric materials. In addition, the mixture
of materials can include no greater than about 99% by weight of the
one or more petrochemical-based polymeric materials, no greater
than about 95% by weight of the one or more petrochemical-based
polymeric materials, no greater than about 90% by weight of the one
or more petrochemical-based polymeric materials, no greater than
about 85% by weight of the one or more petrochemical-based
polymeric materials, no greater than about 80% by weight of the one
or more petrochemical-based polymeric materials, no greater than
about 75% by weight of the one or more petrochemical-based
polymeric materials, no greater than about 70% by weight of the one
or more petrochemical-based polymeric materials, no greater than
about 65% by weight of the one or more petrochemical-based
polymeric materials, or no greater than about 60% by weight of the
one or more petrochemical-based polymeric materials. In an
illustrative example, the mixture of materials can include from
about 2% by weight to about 98% by weight of the one or more
petrochemical-based polymeric materials. In another illustrative
example, the mixture of materials can include from about 50% by
weight to about 90% by weight of the one or more
petrochemical-based polymeric materials. In an additional
illustrative example, the mixture of materials can include from
about 65% by weight to about 75% by weight of the one or more
petrochemical-based polymeric materials. In a further illustrative
example, the mixture of materials can include from about 20% by
weight to about 50% by weight of the one or more
petrochemical-based polymeric materials. In still another
illustrative example, the mixture of materials can include from
about 40% by weight to about 60% by weight of the one or more
petrochemical-based polymeric materials.
[0094] In some cases, the mixture of materials can include a blend
of a first petrochemical-based polymeric material and a second
petrochemical based polymeric material, where the second
petrochemical-based polymeric material can be compostable. That is,
in some cases, the second petrochemical-based polymeric material
can be compostable according to the ASTM D-6400 standard at the
time of filing of this patent application.
[0095] In an implementation, when the mixture of materials includes
a first petrochemical-based polymeric material and a second
petrochemical-based polymeric material, the mixture of materials
can include at least about 10% by weight of the first
petrochemical-based polymeric material, at least about 15% by
weight of the first petrochemical-based polymeric material, at
least about 20% by weight of the first petrochemical-based
polymeric material, or at least about 25% by weight of the first
petrochemical-based polymeric material. Additionally, when the
mixture of materials includes a first petrochemical-based polymeric
material and a second petrochemical-based polymeric material, the
mixture of materials can include no greater than about 50% by
weight of the first petrochemical-based polymeric material, no
greater than about 45% by weight of the first petrochemical-based
polymeric material, no greater than about 40% by weight of the
first petrochemical-based polymeric material, no greater than about
35% by weight of the first petrochemical-based polymeric material,
or no greater than about 30% by weight of the first
petrochemical-based polymeric material. In an illustrative example
when the mixture of materials includes a first petrochemical-based
polymeric material and a second petrochemical-based polymeric
material, the mixture of materials can include from about 5% by
weight to about 55% by weight of the first petrochemical-based
polymeric material. In another illustrative example when the
mixture of materials includes a first petrochemical-based polymeric
material and a second petrochemical-based polymeric material, the
mixture of materials can include from about 10% by weight to about
30% by weight of the first petrochemical-based polymeric material.
In an additional illustrative example when the mixture of materials
includes a first petrochemical-based polymeric material and a
second petrochemical-based polymeric material, the mixture of
materials can include from about 12% by weight to about 20% by
weight of the first petrochemical-based polymeric material. In some
instances, the first petrochemical-based polymeric material can
include a polyethylene. To illustrate, the first
petrochemical-based polymeric material can include a linear low
density polyethylene. In some cases, the first petrochemical-based
polymeric material may not be compostable according to the ASTM
D-6400 standard.
[0096] Furthermore, when the mixture of materials includes a first
petrochemical-based polymeric material and a second
petrochemical-based polymeric material, the mixture of materials
can include at least about 25% by weight of the second
petrochemical-based polymeric material, at least about 30% by
weight of the second petrochemical-based polymeric material, at
least about 35% by weight of the second petrochemical-based
polymeric material, at least about 40% by weight of the second
petrochemical-based polymeric material, or at least about 45% by
weight of the second petrochemical-based polymeric material. Also,
when the mixture of materials includes a first petrochemical-based
polymeric material and a second petrochemical-based polymeric
material, the mixture of materials can include no greater than
about 75% by weight of the second petrochemical-based polymeric
material, no greater than about 70% by weight of the second
petrochemical-based polymeric material, no greater than about 65%
by weight of the second petrochemical-based polymeric material, no
greater than about 60% by weight of the second petrochemical-based
polymeric material, no greater than about 55 by weight of the
second petrochemical-based polymeric material, or no greater than
about 55% by weight of the second petrochemical-based polymeric
material, or no greater than about 50% by weight of the second
petrochemical-based polymeric material. In an illustrative example
when the mixture of materials includes a first petrochemical-based
polymeric material and a second petrochemical-based polymeric
material, the mixture of materials can include from about 20% by
weight to about 80% by weight of the second petrochemical-based
polymeric material. In another illustrative example when the
mixture of materials includes a first petrochemical-based polymeric
material and a second petrochemical-based polymeric material, the
mixture of materials can include from about 35% by weight to about
60% by weight of the second petrochemical-based polymeric material.
In an additional illustrative example when the mixture of materials
includes a first petrochemical-based polymeric material and a
second petrochemical-based polymeric material, the mixture of
materials can include from about 45% by weight to about 55% by
weight of the second petrochemical-based polymeric material.
[0097] In particular implementations when the mixture of materials
includes a first petrochemical-based polymeric material and a
second petrochemical-based polymeric material, the mixture of
materials can include from about 5% by weight to about 25% by
weight of the first petrochemical-based polymeric material and from
about 40% by weight to about 60% by weight of the second
petrochemical-based polymeric material. In other implementations
when the mixture of materials includes a first petrochemical-based
polymeric material and a second petrochemical-based polymeric
material, the mixture of materials can include from about 10% by
weight to about 20% by weight of the first petrochemical-based
polymeric material and from about 45% by weigh to about 55% by
weight of the second petrochemical-based polymeric material.
[0098] In some embodiments, a compatibilizer can also be present in
the mixture of materials. In a particular implementation, a
compatibilizer can be mixed with the one or more
petrochemical-based polymeric materials and the one or more
carbohydrate-based polymeric materials and be included in the
mixture of materials. The compatibilizer can be a modified
polyolefin, such as a maleic anhydride grafted polypropylene, a
maleic anhydride grafted polyethylene, a maleic anhydride grafted
polybutene, or a combination thereof. The compatibilizer can also
include an acrylate based co-polymer. For example, the
compatibilizer can include an ethylene methyl acrylate co-polymer,
an ethylene butyl-acrylate co-polymer, or an ethylene ethyl
acrylate co-polymer. Additionally, the compatibilizer can include a
poly(vinyacetate) based compatibilizer. In an embodiment, the
compatibilizer may be a grafted version of the petrochemical-based
polymeric material (e.g., maleic anhydride grafted polyethylene
where the petrochemical-based polymeric material is
polyethylene).
[0099] In an implementation, the mixture of materials (e.g.,
carbohydrate-based polymeric material, petrochemical-based
polymeric material, and compatibilizer) can include at least about
0.5% by weight of a compatibilizer, at least about 1% by weight of
a compatibilizer, at least about 2% by weight of a compatibilizer,
at least about 3% by weight of a compatibilizer, at least about 4%
by weight of a compatibilizer, or at least about 5% by weight of a
compatibilizer. Additionally, the mixture of materials can include
no greater than about 50% by weight compatilizer, no greater than
about 40% by weight compatilizer, no greater than about 30% by
weight compatilizer, no greater than about 20% by weight
compatilizer no greater than about 10% by weight of a
compatibilizer, no greater than about 9% by weight of a
compatibilizer, no greater than about 8% by weight of a
compatibilizer, no greater than about 7% by weight of a
compatibilizer, or no greater than about 6% by weight of a
compatibilizer. In an illustrative example, the mixture of
materials can include from about 0.5% by weight to about 12% by
weight of a compatibilizer. In another illustrative example, the
mixture of materials can include from about 2% by weight to about
7% by weight of a compatibilizer. In an additional illustrative
example, the mixture of materials can include from about 4% by
weight to about 6% by weight of a compatibilizer. As noted, in some
implementations, it may be possible to employ far higher fractions
of a compatibilizer (e.g., as up to 50%).
[0100] In other implementations, the mixture of materials can
include at least about 0.5% by weight of a compatibilizer, at least
about 3% by weight of a compatibilizer, at least about 10% by
weight of a compatibilizer, at least about 15% by weight of a
compatibilizer, at least about 20% by weight of a compatibilizer,
or at least about 25% by weight of a compatibilizer. In addition,
the mixture of materials can include no greater than about 50% by
weight of a compatibilizer, no greater than about 45% by weight of
a compatibilizer, no greater than about 40% by weight of a
compatibilizer, no greater than about 35% by weight of a
compatibilizer, or no greater than about 30% by weight of a
compatibilizer. In an illustrative example, the mixture of
materials can include from about 0.1% by weight to about 50% by
weight of a compatibilizer. In another illustrative example, the
mixture of materials can include from about 1% by weight to about
35% by weight of a compatibilizer. In an additional illustrative
example, the mixture of materials can include from about 2% by
weight to about 15% by weight of a compatibilizer. In a further
illustrative example, the mixture of materials can include from
about 3% by weight to about 7% by weight of a compatibilizer.
[0101] Although certainly not required, and in at least some
embodiments the inclusion of such would be best avoided, it is
within the scope of the present invention to include any of a
variety of UV and OXO degradable additives, such as PDQ-M, PDQ-H,
BDA, and OxoTerra.TM. from Willow Ridge Plastics, OX1014 from
LifeLine, or organic additives such as Enso Restore.RTM. by Enso,
EcoPure.RTM. by Bio-Tec Environmental, ECM Masterbatch Pellets 1M
by ECM Biofilms, or Biodegradable 201 and/or Biodegradable 302
BioSphere.RTM.. That said, test results included herein show that
inclusion of ESR carbohydrate-based polymeric materials in the
mixture, without addition of other biodegradation additives, can
provide excellent biodegradation results to the films or other
articles formed from the carbohydrate-based polymeric material, a
compatibilizer, and the petrochemical-based polymeric material
without any need for such addition. Also, other additives that
improve strength characteristics of the article can be added to the
mixture of materials. Additives such as Biomax.RTM. Strong from
Dupont can be used. In various embodiments, one or more additives
can be included in the mixture of materials in an amount of at
least about 0.5% by weight, at least about 1% by weight, at least
about 1.5% by weight, at least about 2% by weight, at least about
2.5% by weight, at least about 3% by weight, or at least about 4%
by weight. In further embodiments, one or more additives can be
present in the mixture of materials in an amount of no greater than
about 10% by weight, no greater than about 9% by weight, no greater
than about 8% by weight, no greater than about 7% by weight, no
greater than about 6% by weight, or no greater than about 5% by
weight. In an illustrative example, one or more additives can be
present in the mixture of materials in an amount from about 0.2% by
weight to about 12% by weight. In another illustrative example, one
or more additives can be present in the mixture of materials in an
amount from about 1% by weight to about 10% by weight. In an
additional example, one or more additives can be present in the
mixture of materials in an amount from about 0.5% by weight to
about 4% by weight. In a further illustrative example, one or more
additives can be present in the mixture of materials in an amount
from about 2% by weight to about 6% by weight.
[0102] While principally described in the context of a mixture of
thermoplastic materials that can be melted together, to form a
desired blend, in some embodiments, it may be possible to blend the
carbohydrate-based polymeric material with a plastic material that
is not thermoplastic (e.g., that is thermoset, e.g., such as for
silicone). For example, the resin components that are precursors of
such non-thermoplastic plastic material may be blended with the
carbohydrate-based polymeric material, where polymerization or
other formation of the non-thermoplastic material may occur in the
presence of the carbohydrate-based polymeric material, resulting in
a finished article that is a blend of the carbohydrate-based
polymeric material and a thermoset plastic material, where the
carbohydrate-based polymeric material may lend biodegradability to
the non-thermoplastic plastic material upon blending of the two
together.
[0103] Referring to FIG. 1, at 108, particularly where the
materials are thermoplastic, the process 100 may include heating
the mixture of materials. In an implementation, the mixture of
materials can be heated to a temperature of at least about
100.degree. C., at least about 110.degree. C., at least about
115.degree. C., at least about 120.degree. C., at least about
125.degree. C., at least about 130.degree. C., at least about
135.degree. C., at least about 140.degree. C., or at least about
145.degree. C. In another implementation, the mixture of materials
can be heated to a temperature no greater than about 200.degree.
C., no greater than about 190.degree. C., no greater than about
180.degree. C., no greater than about 175.degree. C., no greater
than about 170.degree. C., no greater than about 165.degree. C., no
greater than about 160.degree. C., no greater than about
155.degree. C., or no greater than about 150.degree. C. In an
illustrative example, the mixture of materials can be heated to a
temperature from about 95.degree. C. to about 205.degree. C. In
another illustrative example, the mixture of materials can be
heated to a temperature from about 120.degree. C. to about
180.degree. C. In an additional illustrative example, the mixture
of materials can be heated to a temperature from about 125.degree.
C. to about 165.degree. C.
[0104] The mixture of materials including the petrochemical based
polymeric material and carbohydrate-based polymeric material can be
heated in one or more chambers of an extruder. In some cases, one
or more chambers of the extruder can be heated at different
temperatures. In other cases, one or more chambers of the extruder
can be heated at substantially a same temperature. In various
embodiments, the extruder can have at least one chamber, at least
two chambers, at least three chambers, at least four chambers, at
least five chambers, at least six chambers, at least seven
chambers, at least eight chambers, at least nine chambers, or at
least ten chambers. In other embodiments, the extruder can have one
chamber, two chambers, three chambers, four chambers, five
chambers, six chambers, seven chambers, eight chambers, nine
chambers, or ten chambers. In further embodiments, the extruder can
have less than three chambers, less than four chambers, less than
five chambers, less than six chambers, less than seven chambers,
less than eight chambers, less than nine chambers, or less than ten
chambers.
[0105] The speed of one or more screws of the extruder can be at
least about 10 rotations per minute (rpm), at least about 12 rpm,
at least about 14 rpm, at least about 16 rpm, or at least about 18
rpm. Additionally, the speed of one or more screws of the extruder
can be no greater than about 30 rpm, no greater than about 28 rpm,
no greater than about 26 rpm, no greater than about 24 rpm, no
greater than about 22 rpm, or no greater than about 20 rpm. In an
illustrative example, the speed of one or more screws of the
extruder can be from about 8 rpm to about 35 rpm. In another
illustrative example, the speed of one or more screws of the
extruder can be from about 12 rpm to about 25 rpm. In an additional
illustrative example, the speed of one or more screws of the
extruder can be from about 14 rpm to about 21 rpm.
[0106] At 110, an article is produced using the mixture of
materials. In some cases, the article can include a film. In other
cases, the article can be formed from a film. In other embodiments,
the article can have a shape based on a design, such as a mold
(e.g., injection molded). Any conceivable article formed of plastic
may be formed from the mixture, e.g., including but not limited to
films, bags, bottles, caps, lids, sheets, boxes, plates, cups,
utensils, and the like. Where the article is a film, the film can
be formed using a die by injecting a gas into the heated mixture of
material to form the film (i.e., blowing the film). Films can be
sealed and/or otherwise modified to be in the form of a bag or
other article.
[0107] In an implementation, the article can have from about 10% by
weight to about 95% by weight of one or more petrochemical-based
polymeric materials, from about 20% by weight to about 80% by
weight of one or more petrochemical-based polymeric materials, from
about 30% by weight to about 70% by weight of one or more
petrochemical-based polymeric materials, or from about 40% by
weight to about 60% by weight of one or more petrochemical-based
polymeric materials. In an illustrative example, the article can
have from about 60% by weight to about 80% by weight of one or more
petrochemical-based polymeric materials. In some cases, the article
can include a mixture of a first petrochemical-based polymeric
material and a second petrochemical-based polymeric material, where
the second petrochemical-based polymeric material is compostable.
In these situations, the article can include from about 5% by
weight to about 30% by weight of the first petrochemical-based
polymeric material and from about 35% by weight to about 60% by
weight of the second petrochemical-based polymeric material. In
another implementation, the article can include from about 10% by
weight to about 20% by weight of the first petrochemical-based
polymeric material and from about 45% by weight to about 55% by
weight of the second petrochemical-based polymeric material.
[0108] Additionally, the article can have from about 10% by weight
to about 98% by weight of one of more carbohydrate-based polymeric
materials, from about 20% by weight to about 80% by weight of one
or more carbohydrate-based polymeric materials, from about 30% by
weight to about 70% by weight of one or more carbohydrate-based
polymeric materials, or from about 40% by weight to about 60% by
weight of one or more carbohydrate-based polymeric materials. In an
illustrative example, the article can include from about 15% by
weight to about 30% by weight of one or more carbohydrate-based
polymeric materials. In another illustrative example, the article
can include from about 10% by weight to about 25% by weight of one
or more carbohydrate-based polymeric materials. In a particular
implementation, the article can include at least about 95% by
weight of one or more carbohydrate-based polymeric materials or at
least about 99% by weight of one or more carbohydrate-based
polymeric materials.
[0109] In embodiments where the article is a film, the film can be
comprised of a single layer, in some cases, and multiple layers, in
other cases. One or more layers of the film can have a thickness of
at least about 0.01 mm, at least about 0.02 mm, at least about 0.03
mm, at least about 0.05 mm, at least about 0.07 mm, at least about
0.10 mm, at least 0.2 mm, at least about 0.5 mm, at least about 0.7
mm, at least about 1 mm, at least about 2 mm, or at least about 5
mm. Additionally, when the article is a film, one or more layers of
the film can have a thickness of no greater than about 2 cm, no
greater than about 1.5 cm, no greater than about 1 cm, no greater
than about 0.5 cm, no greater than about 100 mm, no greater than
about 80 mm, no greater than about 60 mm, no greater than about 40
mm, no greater than about 30 mm, no greater than about 20 mm, or no
greater than about 10 mm. In an illustrative example, when the
article is a film, one or more layers of the film can have a
thickness as little as about 0.1 mil (0.0025 mm), or from about
0.005 mm to about 3 cm. In another illustrative example, when the
article is a film, one or more layers of the film can have a
thickness from about 0.01 mm to about 1 mm. In an additional
illustrative example, when the article is a film, one or more
layers of the film can have a thickness from about 0.05 mm to about
0.5 mm. In a further illustrative example, when the article is a
film, one or more layers of the film can have a thickness from
about 0.02 mm to about 0.05 mm. Those of skill in the art will
appreciate that some such thickness values may more commonly be
termed "sheets", rather than films. Film is used herein
broadly.
[0110] The article can have strength characteristics that are
characterized through testing, such as a dart drop impact test
(ASTM D-1709), tensile strength at break test (ASTM D-882), tensile
elongation at break test (ASTM D-882), a secant modulus test (ASTM
D-882), and/or an Elmendorf Tear test (ASTM D-1922). In an
implementation, the article can have a dart drop impact test value
of at least about 150 g, at least about 175 g, at least about 200
g, at least about 225 g, at least about 250 g, at least about 275
g, or at least about 300 g. In another implementation, the article
can have a dart drop impact test value of no greater than about 400
g, no greater than about 375 g, no greater than about 350 g, or no
greater than about 325 g. In an illustrative implementation, the
article can have a dart drop impact test value from about 140 g to
about 425 g. In another illustrative implementation, the article
can have a dart drop impact test value from about 200 g to about
400 g. In an additional illustrative example, the article can have
a dart drop impact test value from about 250 g to about 350 g. In a
further illustrative example, the article can have a dart drop
impact test value from about 265 g to about 330 g. In an
implementation, such values may be for whatever the thickness of
the film. In another implementation, such values may be per mil of
thickness.
[0111] In an implementation, the article can have a tensile
strength at break test value in the machine direction of at least
about 3.5 kpsi, at least about 3.7 kpsi, at least about 3.9 kpsi,
at least about 4.1 kpsi, at least about 4.3 kpsi, or at least about
4.5 kpsi. In another implementation, the article can have a tensile
strength at break test value in the machine direction of no greater
than about 5.5 kpsi, no greater than about 5.3 kpsi, no greater
than about 5.1 kpsi, no greater than about 4.9 kpsi, or no greater
than about 4.7 kpsi. In an illustrative example, the article can
have a tensile strength at break test value in the machine
direction from about 3.5 kpsi to about 5.5 kpsi. In another
illustrative example, the article can have a tensile strength at
break test value in the machine direction from about 4.1 kpsi to
about 4.9 kpsi.
[0112] In an implementation, the article can have a tensile
strength at break test value in the transverse direction of at
least about 3.2 kpsi, at least about 3.4 kpsi, at least about 3.6
kpsi, at least about 3.8 kpsi, at least about 4.0 kpsi, or at least
about 4.2 kpsi. In another implementation, the article can have a
tensile strength at break test value in the transverse direction of
no greater than about 5.7 kpsi, no greater than about 5.5 kpsi, no
greater than about 5.3 kpsi, no greater than about 5.1 kpsi, no
greater than about 4.9 kpsi, no greater than about 4.7 kpsi, or no
greater than about 4.5 kpsi. In an illustrative example, the
article can have a tensile strength at break test value in the
transverse direction from about 3.2 kpsi to about 5.7 kpsi. In
another illustrative example, the article can have a tensile
strength at break test value in the transverse direction from about
3.6 kpsi to about 5.0 kpsi.
[0113] In an implementation, the article can have a tensile
elongation at break test value in the machine direction of at least
about 550%, at least about 560%, at least about 570%, at least
about 580%, at least about 590%, at least about.sup.600%, at least
about 610%, or at least about 620%. In another implementation, the
article can have a tensile elongation at break test value in the
machine direction of no greater than about 725%, no greater than
about 710%, no greater than about 700%, no greater than about 680%,
no greater than about 665%, no greater than about 650%, or no
greater than about 635%. In an illustrative example, the article
can have a tensile elongation at break test value in the machine
direction from about 550% to about 750%. In another illustrative
example, the article can have a tensile elongation at break test
value in the machine direction from about 600% to about 660%.
[0114] In an implementation, the article can have a tensile
elongation at break test value in the transverse direction of at
least about 575%, at least about 590%, at least about 600%, at
least about 615%, at least about 630%, or at least about 645%. In
another implementation, the article can have a tensile elongation
at break test value in the transverse direction of no greater than
about 770%, no greater than about 755%, no greater than about 740%,
no greater than about 725%, no greater than about 710%, no greater
than about 695%, or no greater than about 680%. In an illustrative
example, the article can have a tensile elongation at break test
value in the transverse direction from about 575% to about 775%. In
another illustrative example, the article can have a tensile
elongation at break test value in the transverse direction from
about 625% to about 700%.
[0115] In an implementation, the article can have an Elmendorf tear
force test value in the machine direction of at least about 280
g/mil, at least about 300 g/mil, at least about 320 g/mil, at least
about 340 g/mil, or at least about 360 g/mil. In another
implementation, the article can have an Elmendorf tear force test
value in the machine direction of no greater than about 450 g/mil,
no greater than about 430 g/mil, no greater than about 410 g/mil,
no greater than about 390 g/mil, or no greater than about 370
g/mil. In an illustrative example, the article can have an
Elmendorf tear force test value in the machine direction from about
275 g/mil to about 475 g/mil. In another illustrative example, the
article can have an Elmendorf tear force test value in the machine
direction from about 325 g/mil to about 410 g/mil.
[0116] In an implementation, the article can have an Elmendorf tear
force test value in the transverse direction of at least about 475
g/mil, at least about 490 g/mil, at least about 500 g/mil, at least
about 525 g/mil, at least about 540 g/mil, or at least about 550
g/mil. In another implementation, the article can have an Elmendorf
tear force test value in the transverse direction of no greater
than about 700 g/mil, no greater than about 680 g/mil, no greater
than about 650 g/mil, no greater than about 625 g/mil, no greater
than about 600 g/mil, no greater than about 580 g/mil, or no
greater than about 570 g/mil. In an illustrative example, the
article can have an Elmendorf tear force test value in the
transverse direction from about 475 g/mil to about 725 g/mil. In
another illustrative example, the article can have an Elmendorf
tear force test value in the transverse direction from about 490
g/mil to about 640 g/mil.
[0117] In an implementation, the article can have a secant modulus
of elasticity test value in the machine direction of at least about
20 kpsi, at least about 22 kpsi, at least about 24 kpsi, at least
about 26 kpsi, at least about 28 kpsi, or at least about 30 kpsi.
In another implementation, the article can have a secant modulus of
elasticity test value in the machine direction of no greater than
about 40 kpsi, no greater than about 38 kpsi, no greater than about
36 kpsi, no greater than about 34 kpsi, or no greater than about 32
kpsi. In an illustrative example, the article can have a secant
modulus of elasticity test value in the machine direction from
about 20 kpsi to about 40 kpsi. In another illustrative example,
the article can have a secant modulus of elasticity test value in
the machine direction from about 25 kpsi to about 35 kpsi.
[0118] In an implementation, the article can have a secant modulus
of elasticity test value in the transverse direction of at least
about 20 kpsi, at least about 22 kpsi, at least about 24 kpsi, at
least about 26 kpsi, at least about 28 kpsi, or at least about 30
kpsi. In another implementation, the article can have a secant
modulus of elasticity test value in the transverse direction of no
greater than about 40 kpsi, no greater than about 38 kpsi, no
greater than about 36 kpsi, no greater than about 34 kpsi, or no
greater than about 32 kpsi. In an illustrative example, the article
can have a secant modulus of elasticity test value in the
transverse direction from about 20 kpsi to about 40 kpsi. In
another illustrative example, the article can have a secant modulus
of elasticity test value in the transverse direction from about 25
kpsi to about 35 kpsi.
[0119] In some cases, articles including a carbohydrate-based
polymeric material formed from a mixture of two or more starches
have values of strength properties that are greater than articles
including a carbohydrate-based polymeric material formed from a
single starch. For example, an article including a
carbohydrate-based polymeric material formed from a mixture of two
or more starches can have a dart drop impact test value (in grams
or g/mil of thickness) that is at least about 10% greater than an
article where the carbohydrate-based polymeric material is formed
from a single starch, at least about 25% greater than an article
where the carbohydrate-based polymeric material is formed from a
single starch, at least about 50% greater than an article where the
carbohydrate-based polymeric material is formed from a single
starch, at least about 75% greater than an article where the
carbohydrate-based polymeric material is formed from a single
starch, or at least about 90% greater than an article where the
carbohydrate-based polymeric material is formed from a single
starch. In another example, an article including a
carbohydrate-based polymeric material formed from a mixture of two
or more starches can have a dart drop impact test value that is no
greater than about 150% greater than an article where the
carbohydrate-based polymeric material is formed from a single
starch, no greater than about 140% greater than an article where
the carbohydrate-based polymeric material is formed from a single
starch, no greater than about 130% greater than an article where
the carbohydrate-based polymeric material is formed from a single
starch, no greater than about 130% greater than an article where
the carbohydrate-based polymeric material is formed from a single
starch, no greater than about 120% greater than an article where
the carbohydrate-based polymeric material is formed from a single
starch, or no greater than at least about 110% greater than an
article where the carbohydrate-based polymeric material is formed
from a single starch. In an illustrative example, an article
including a carbohydrate-based polymeric material formed from a
mixture of two or more starches can have a dart drop impact test
value that is from at least about 10% to about 150% greater than an
article where the carbohydrate-based polymeric material is formed
from a single starch. In another illustrative example, an article
where the carbohydrate-based polymeric material is formed from a
mixture of two or more starches can have a dart drop impact test
value that is from at least about 60% to about 120% greater than an
article including a carbohydrate-based polymeric material formed
from a single starch.
[0120] In various embodiments, an article including a
carbohydrate-based polymeric material formed from a mixture of a
first starch and a second starch can have a strength test value
that is greater than an otherwise comparable article including a
starch-based polymeric material formed from only the first or
second starch, without the presence of two different starches. For
example, an article including a carbohydrate-based polymeric
material formed from a mixture of a first starch and a second
starch (e.g., potato starch and another starch) can have a dart
drop impact test value that is greater than a first dart drop
impact test value of an otherwise comparable article where the
starch-based polymeric material is formed from only a single starch
(e.g., just potato starch, or just the other starch). In other
words, where the starch-based polymeric material that goes into the
article is formed from two or more types of starches the resulting
strength is greater than if either starch were used alone to make
the starch-based polymeric material. There is thus a synergistic
strengthening effect that is achieved when using two or more
different starches to make the starch-based polymeric material that
is included in the article.
[0121] In further implementations, an article including a
carbohydrate-based polymeric material formed from a mixture of a
first starch and a second starch can have a strength test value
that is greater than a strength test value of an article formed
from a petrochemical-based polymeric material without the
carbohydrate-based polymeric material. For example, an article
including a carbohydrate-based polymeric material formed from a
mixture of a first starch and a second starch can have a tensile
elongation at break test value in the machine direction that is
greater than a tensile elongation at break test value in the
machine direction of an article formed from a petrochemical-based
polymeric material without the carbohydrate-based polymeric
material. Increased strength results can be measured for dart drop
impact strength, tensile strength at break, secant modulus
strength, and/or Elmendorf Tear strength. Other strength tests
could similarly show such improvements.
[0122] In an implementation, when subjected to biodegradation
testing, an article being substantially free of a biodegradation
enhancing additive and having from about 20% by weight to about 40%
by weight of one or more carbohydrate-based polymeric materials and
from about 65% by weight to about 85% by weight of one or more
petrochemical-based polymeric materials can have an amount of
biodegradation after 32 days of testing under a biomethane
potential test from about 10% to about 22%. In another
implementation, when subjected to biomethane potential testing, an
article being substantially free of a biodegradation enhancing
additive and having from about 20% by weight to about 40% by weight
of one or more carbohydrate-based polymeric materials and from
about 65% by weight to about 85% by weight of one or more
petrochemical-based polymeric materials can have an amount of
biodegradation after 62 days of testing under a biomethane
potential test from about 25% to about 35%. In an additional
implementation, when subjected to biodegradation testing, an
article being substantially free of a biodegradation enhancing
additive and having from about 20% by weight to about 40% by weight
of one or more carbohydrate-based polymeric materials and from
about 65% by weight to about 85% by weight of one or more
petrochemical-based polymeric materials can have an amount of
biodegradation after 91 days of testing under a biomethane
potential test from about 30% to about 40%. While the above
percentages may result under biomethane potential testing
conditions, it will be appreciated that such simulated conditions
are not required, and that of course such biodegradation may also
result under other testing conditions (e.g., under any appropriate
ASTM or similar conditions meant to simulate landfill, composting,
and/or marine conditions), over an appropriate period of time
(e.g., 90 days, 180 days, 1 year, 2 years, 3 years, 5 years, or the
like).
[0123] Particularly when subjecting the present articles to testing
simulating biodegradation under landfill or other degradation
conditions (e.g., composting conditions, or marine conditions) for
greater periods of time (e.g., 180 days, 200 days, 365 days (1
year), within 2 years, or within 3 years), the biodegradation can
be greater than the weight percent of carbohydrate-based polymeric
materials within the article. In other words, inclusion of the
described carbohydrate-based polymeric materials can result in at
least some biodegradation of the petrochemical-based polymeric
material (which materials alone are not biodegradable). For
example, an article that is a film formed from a blend of the
carbohydrate-based polymeric materials and LLDPE (e.g., a bag), may
exhibit biodegradation after such periods of time that is greater
than the weight fraction of the carbohydrate-based polymeric
materials in the film, indicating that the LLDPE (heretofore
considered to not be biodegradable) is actually being biodegraded,
with the carbohydrate-based polymeric material. Such results are
surprising, and particularly advantageous. For example, such a bag
or other film article not only exhibits increased environmental
sustainability (as a significant fraction thereof is sourced from a
renewable starch material), but it now also exhibits
biodegradability characteristics, where the comparable bag or other
film formed from 100% LLDPE (or even a blend of conventional TPS
and LLDPE) did not have such characteristics. Furthermore, as
described above, the strength of the bag or film can be greater
than that of the 100% LLDPE bag or film. Even cost can be
comparable. Such a collection of characteristics marks a
significant advancement in the art.
[0124] The biomethane potential testing can determine the potential
for anaerobic biodegradation based on methanogenesis as a percent
of total methanogenesis potential. In some cases, the biomethane
potential testing can be used to predict biodegradability of the
tested samples according to the ASTM D-5511 standard and the
biomethane potential testing can be conducted using one or more
conditions from the ASTM D-5511 standard. For example, the
biomethane potential testing can take place at a temperature of
about 52.degree. C. Additionally, the biomethane potential testing
can have some conditions that are different from those of ASTM
D-5511. In an implementation, the biomethane potential testing can
utilize an inoculum having from about 50% by weight water to about
60% by weight water and from about 40% by weight organic solids to
about 50% by weight organic solids. In a particular illustrative
example, the inoculum used in biomethane potential testing can have
about 55% by weight water and about 45% by weight organic solids.
Biomethane potential testing can also take place at other
temperatures, such as from about 35.degree. C. to about 55.degree.
C. or from about 40.degree. C. to about 50.degree. C.
[0125] In various implementations, an article being substantially
free of a biodegradation enhancing additive and having from about
20% by weight to about 40% by weight of one or more
carbohydrate-based polymeric materials and from about 65% by weight
to about 85% by weight of one or more petrochemical-based polymeric
materials can have an amount of biodegradation after 91 days of
testing under a biomethane potential test (or other biodegradation
test conditions) that is greater than an amount of the one or more
carbohydrate based polymeric materials present in the article. For
example, an amount of biodegradation of an article being
substantially free of a biodegradation enhancing additive and
having from about 20% by weight to about 40% by weight of one or
more carbohydrate-based polymeric materials and from about 65% by
weight to about 85% by weight of one or more petrochemical-based
polymeric materials can have an amount of biodegradation after 91
days of testing under a biomethane potential test (or other
biodegradation test conditions) that is from about 5% to about 60%,
from about 10% to about 50%, or from about 15% to about 40% greater
than the amount of the one or more carbohydrate-based polymeric
materials present in the article.
[0126] In other implementations, an article being substantially
free of a biodegradation enhancing additive and having from about
95% by weight to substantially all of one or more
carbohydrate-based polymeric materials can have an amount of
biodegradation after 32 days of testing under a biomethane
potential test from about 30% to about 45%. Further, an article
being substantially free of a biodegradation enhancing additive and
having from about 95% by weight to substantially all of one or more
carbohydrate-based polymeric materials can have an amount of
biodegradation after 62 days of testing under a biomethane
potential test from about 40% to about 55%. In additional
implementations, an article being substantially free of a
biodegradation enhancing additive and having from about 95% by
weight to substantially all of one or more carbohydrate-based
polymeric materials can have an amount of biodegradation after 91
days of testing under a biomethane potential test from about 48% to
about 62%.
[0127] In addition, when subjected to biodegradation testing, an
article having no greater than about 2% by weight of a
biodegradation enhancing additive and having from about 20% by
weight to about 40% by weight of one or more carbohydrate-based
polymeric materials and from about 65% by weight to about 85% by
weight of one or more petrochemical-based polymeric materials can
have an amount of biodegradation after 32 days of testing under a
biomethane potential test from about 9% to about 20%. In another
implementation, when subjected to biodegradation testing, an
article having no greater than about 2% by weight of a
biodegradation enhancing additive and having from about 20% by
weight to about 40% by weight of one or more carbohydrate-based
polymeric materials and from about 65% by weight to about 85% by
weight of one or more petrochemical-based polymeric materials can
have an amount of biodegradation after 62 days of testing under a
biomethane potential test from about 20% to about 32%. In an
additional implementation, when subjected to biodegradation
testing, an article having no greater than about 2% by weight of a
biodegradation enhancing additive and having from about 20% by
weight to about 40% by weight of one or more carbohydrate-based
polymeric materials and from about 65% by weight to about 85% by
weight of one or more petrochemical-based polymeric materials can
have an amount of biodegradation after 91 days of testing under a
biomethane potential test from about 37% to about 50%. In various
situations, biodegradation test values can also be determined using
ASTM standards, such as ASTM D-6400, ASTM D-5338, ASTM D-5988, ASTM
D-5511, ASTM D-7475, ASTM D-5526 or ASTM D-6691.
[0128] In addition, an article can be subjected to compostability
testing. Compostability of articles can be performed in accordance
with the ASTM D-6400 test at the time of filing of this patent
application. In some cases, phytotoxicity corresponding to the
biodegradation of articles can be measured, biodegradation of
articles can be measured, an elemental/metals analysis with regard
to the articles can be performed, or a combination thereof.
[0129] Articles produced using the process 100 can pass the
phytotoxicity component of the ASTM D-6400 test. For example, a
biomass in which the article has at least partially degraded can be
used to germinate plant seeds, such as cucumber seeds and/or
soybean seeds. The length of the germinated plants can be measured
and compared to a threshold length to determine if the article
passes the phytotoxicity portion of the ASTM D-6400 test. In a
particular implementation, a length of a cucumber plant germinated
from seed in a biomass of an article produced according to the
process 100 can be from about 58 mm to about 75 mm. Additionally, a
length of a soybean plant germinated from seed in a biomass of an
article produced according to the process 100 can be from about 135
mm to about 175 mm.
[0130] As part of the elemental analysis component of the ASTM
D-6400 test, an analysis of elements included in a biomass of
articles produced using the process 100 can be performed. For
example, amounts of one or more of the following elements can be
measured: arsenic, cadmium, copper, lead, mercury, nickel,
selenium, or zinc. The amounts measured for each of the elements
can be compared to a threshold amount to determine whether the
sample passed the elemental analysis portion of the ASTM D-6400
test for the respective elements.
[0131] Also, when articles produced according to the process 100
are subjected to compostability testing under the ASTM D-6400
standard, an amount of CO.sub.2 emitted in the test chamber after
98 days can be measured and can be at least about 10% of
theoretical maximum CO.sub.2 emissions, at least about 12% of
theoretical maximum CO.sub.2 emissions, at least about 14% of
theoretical maximum CO.sub.2 emissions, at least about 16% of
theoretical maximum CO.sub.2 emissions, at least about 18% of
theoretical maximum CO.sub.2 emissions, at least about 20% of
theoretical maximum CO.sub.2 emissions, at least about 22% of
theoretical maximum CO.sub.2 emissions, at least about 24% of
theoretical maximum CO.sub.2 emissions, or at least about 26% of
theoretical maximum CO.sub.2 emissions. In addition, when articles
produced according to the process 100 are subjected to
compostability testing under the ASTM D-6400 standard, an amount of
CO.sub.2 emitted in the test chamber after 98 days can be no
greater than about 50% of theoretical maximum CO.sub.2 emissions,
no greater than about 48% of theoretical maximum CO.sub.2
emissions, no greater than about 45% of theoretical maximum
CO.sub.2 emissions, no greater than about 42% of theoretical
maximum CO.sub.2 emissions, no greater than about 40% of
theoretical maximum CO.sub.2 emissions, no greater than about 38%
of theoretical maximum CO.sub.2 emissions, no greater than about
35% of theoretical maximum CO.sub.2 emissions, no greater than
about 32% of theoretical maximum CO.sub.2 emissions, or no greater
than about 30% of theoretical maximum CO.sub.2 emissions. In an
illustrative example, when articles produced according to the
process 100 are subjected to compostability testing under the ASTM
D-6400 standard, an amount of CO.sub.2 emitted in the test chamber
after 98 days can be from about 8% of theoretical maximum CO.sub.2
emissions to about 55% of theoretical maximum CO.sub.2 emissions.
In another illustrative example, when articles produced according
to the process 100 are subjected to compostability testing under
the ASTM D-6400 standard, an amount of CO.sub.2 emitted in the test
chamber after 98 days can be from about 15% of theoretical maximum
CO.sub.2 emissions to about 35% of theoretical maximum CO.sub.2
emissions. In an additional illustrative example, when articles
produced according to the process 100 are subjected to
compostability testing under the ASTM D-6400 standard, an amount of
CO.sub.2 emitted in the test chamber after 98 days can be from
about 18% of theoretical maximum CO.sub.2 emissions to about 30% of
theoretical maximum CO.sub.2 emissions.
[0132] Additionally, when subjected to compostability testing under
the ASTM D-6400 standard, an amount of CO.sub.2 emitted in the test
chamber after 180 days can be at least about 35% of theoretical
maximum CO.sub.2 emissions, at least about 40% of theoretical
maximum CO.sub.2 emissions, at least about 45% of theoretical
maximum CO.sub.2 emissions, or at least about 50% of theoretical
maximum CO.sub.2 emissions, or at least about 55% of theoretical
maximum CO.sub.2 emissions. Further, when subjected to
compostability testing under the ASTM D-6400 standard, an amount of
CO.sub.2 emitted in the test chamber after 180 days can be no
greater than about 85% of theoretical maximum CO.sub.2 emissions,
no greater than about 80% of theoretical maximum CO.sub.2
emissions, no greater than about 75% of theoretical maximum
CO.sub.2 emissions, no greater than about 70% of theoretical
maximum CO.sub.2 emissions, no greater than about 65% of
theoretical maximum CO.sub.2 emissions, or no greater than about
60% of theoretical maximum CO.sub.2 emissions. In an illustrative
example, when articles produced according to the process 100 are
subjected to compostability testing under the ASTM D-6400 standard,
an amount of CO.sub.2 emitted in the test chamber after 180 days
can be from about 38% of theoretical maximum CO.sub.2 emissions to
about 87% of theoretical maximum CO.sub.2 emissions. In another
illustrative example, when articles produced according to the
process 100 are subjected to compostability testing under the ASTM
D-6400 standard, an amount of CO.sub.2 emitted in the test chamber
after 180 days can be from about 40% of theoretical maximum
CO.sub.2 emissions to about 60% of theoretical maximum CO.sub.2
emissions. In an additional illustrative example, when articles
produced according to the process 100 are subjected to
compostability testing under the ASTM D-6400 standard, an amount of
CO.sub.2 emitted in the test chamber after 180 days can be from
about 42% of theoretical maximum CO.sub.2 emissions to about 57% of
theoretical maximum CO.sub.2 emissions. In a further illustrative
example, when articles produced according to the process 100 are
subjected to compostability testing under the ASTM D-6400 standard,
an amount of CO.sub.2 emitted in the test chamber after 180 days
can be from about 70% of theoretical maximum CO.sub.2 emissions to
about 80% of theoretical maximum CO.sub.2 emissions. In some
instances, when articles produced according to the process 100 are
subjected to compostability testing under the ASTM D-6400 standard,
an amount of CO.sub.2 emitted in the test chamber after 180 days
with respect to the theoretical maximum CO.sub.2 emissions can be
greater than the portion of the theoretical maximum amount of
CO.sub.2 that can be attributed to an amount of a starch-based
polymeric material included in the articles. Thus, an amount of the
CO.sub.2 emitted in the chamber after 180 days can be attributed to
an amount of a noncompostable petrochemical-based polymeric
material under the ASTM D-6400 standard.
[0133] Although FIG. 1 illustrates one illustrative example of
certain steps of a process usable for producing an article as
disclosed herein, it is to be appreciated that the configuration
and inclusion of certain steps shown in FIG. 1 is only one example.
Although the process 100 has been described with respect to
providing both one or more petrochemical-based polymeric materials
and one or more carbohydrate-based materials, in some instances,
the process 100 can be implemented without providing the one or
more petrochemical-based polymeric materials. Thus, the article can
be formed from the one or more carbohydrate-based polymeric
materials, without any petrochemical-based polymeric material. In
these situations, substantially all of the article can comprise the
one or more carbohydrate-based polymeric materials.
[0134] FIG. 2 illustrates components of an example manufacturing
system 200 to produce articles including biodegradable materials.
In some cases, the manufacturing system 200 can be used in the
process 100 of FIG. 1. In an illustrative example, the
manufacturing system 200 is an extruder, such as a single screw
extruder or a twin screw extruder.
[0135] In an implementation, one or more petrochemical-based
polymeric materials and one or more carbohydrate-based polymeric
materials are provided via a first hopper 202 and a second hopper
204. The one or more petrochemical-based polymeric materials can
include one or more polyolefin-based polymeric materials. For
example, the one or more petrochemical-based polymeric materials
can include a polyethylene. Additionally, the one or more
carbohydrate-based polymeric materials can include one or more
starch-based polymeric materials. In various implementations, the
one or more a carbohydrate-based polymeric materials can be formed
from one or more carbohydrates. In a particular example, the one or
more carbohydrates can include a mixture of starches. To
illustrate, the one or more carbohydrate-based materials can be
formed from an amount of a first starch and an amount of a second
starch. The first starch can be derived from one of potato, corn,
or tapioca and the second starch can be derived from a different
one of potato, corn, or tapioca. Furthermore, the one or more
carbohydrate-based polymeric materials can include an amount of a
third starch that is different from the first starch and the second
starch. In some implementations, the one or more carbohydrate-based
polymeric materials can also be formed from one or more
plasticizers.
[0136] The one or more carbohydrate-based polymeric materials and
the one or more petrochemical-based polymeric materials can be
mixed in a first chamber 206 to produce a mixture of materials. In
some cases, the mixture of materials can include from about 10% by
weight to about 40% by weight of the one or more carbohydrate-based
polymeric materials, from about 60% by weight to about 89% by
weight of the one or more petrochemical-based polymeric materials,
and from about 1% by weight to about 9% by weight of the one or
more compatibilizers.
[0137] In the example implementation shown in FIG. 2, the mixture
of materials can pass through a number of chambers, such as the
first chamber 206, a second chamber 208, a third chamber 210, a
fourth chamber 212, a fifth chamber 214, and an optional sixth
chamber 216. The mixture of materials can be heated in the chambers
206, 208, 210, 212, 214, 216. In some cases, a temperature of one
of the chambers can be different from a temperature of another one
of the chambers. In an illustrative example, the first chamber 206
is heated to a temperature from about 120.degree. C. and about
140.degree. C.; the second chamber 208 is heated to a temperature
from about 130.degree. C. and about 160.degree. C.; the third
chamber 210 is heated to a temperature from about 135.degree. C.
and about 165.degree. C.; the fourth chamber 212 is heated to a
temperature from about 140.degree. C. and about 170.degree. C.; the
fifth chamber 214 is heated to a temperature from about 145.degree.
C. and about 180.degree. C.; and the optional sixth chamber 216 is
heated to a temperature from about 145.degree. C. and about
180.degree. C.
[0138] The heated mixture can then be extruded using a die 218 to
form an extruded object, such as a film. A gas can be injected into
the extruded object to expand it with a pressure from about 105 bar
to about 140 bar. The resulting tube 220 can be drawn up through
rollers 222 to create a film 224 with a thickness typically from
about 0.02 mm (about 0.8 mil) to about 0.05 mm (about 2 mil). Even
thinner films can be made using the blends as described herein,
e.g., having a thickness as little as 0.1 mil (0.0025 mm). Of
course, thicknesses greater than 2 mil can also be achieved. In
some cases, the film 224 can be comprised of a single layer. In
other cases, the film 224 can be comprised of multiple layers. For
example, the film 224 can be comprised of at least 2 layers, at
least 3 layers, at least 4 layers, or at least 6 layers.
Additionally, the film 224 can be comprised of no greater than
about 12 layers, no greater than about 10 layers, or no greater
than about 8 layers. One or more layers may include the
carbohydrate or starch-based polymeric material.
[0139] Optionally, the film 224 can be formed into one or more
bags. A bag formed from the film 224 can have a typical thickness
from about 0.02 mm to about 0.05 mm. As described above, lower
thicknesses can also be achieved. The bag can include a cavity for
holding items. In a particular implementation, a cavity of a bag
formed from the film 224 can have a volume of at least about 0.1 L,
at least about 0.5 L, at least about 1 L, at least about 2 L, or at
least about 5 L. Additionally, a cavity of a bag formed from the
film 224 can have a volume no greater than about 100 L, no greater
than about 75 L, no greater than about 50 L. In an illustrative
example, a cavity of a bag formed from the film 224 can have a
volume from about 1 L to about 100 L. In another illustrative
example, a cavity of a bag formed from the film 224 can have a
volume from about 5 L to about 20 L.
[0140] In an implementation, the film 224 can be formed from a
starch-based polymeric material. In some cases, the starch-based
polymeric material can be formed from a single starch. In other
cases, the starch-based polymeric material can be formed from a
mixture of starches. In some cases, the materials from which the
starch-based polymeric material is formed can include from about
70% by weight to about 90% by weight of the single starch or the
mixture of starches. Additionally, the materials from which the
starch-based polymeric material is formed can include from about
10% by weight to about 30% by weight of a plasticizer, such as
glycerin. In another implantation, about 70% to about 90% of the
starch-based polymeric material may be derived from or attributable
to (formed from) the one or more starch materials. Similarly, about
10% to about 30% of the starch-based polymeric material may be
derived from or attributable to (formed from) the plasticizer. The
starch-based polymeric material can include from about 0.4% by
weight to about 1.5% by weight water.
[0141] In one example, the film 224 can be formed from a
starch-based polymeric material that is formed from about 15% by
weight to about 25% by weight of a first starch, from about 15% by
weight to about 25% by weight of a second starch, and from about
55% by weight to about 65% by weight of a third starch. In another
implementation, such fractions may represent the portion of the
starch based polymeric material that is derived from or
attributable to (formed from) the starch(es). In an illustrative
example, the first starch can include potato starch, the second
starch can include corn starch, and the third starch can include
tapioca starch. In another illustrative example, the first starch
can include tapioca starch, the second starch can include corn
starch, and the third starch can include potato starch. In an
additional illustrative example, the first starch can include
tapioca starch, the second starch can include potato starch, and
the third starch can include corn starch.
[0142] In other implementations, the film 224 can be formed from a
starch-based polymeric material that is formed from about 27% by
weight to about 36% by weight of a first starch, from about 27% by
weight to about 36% by weight of a second starch, and from about
27% by weight to about 36% by weight of a third starch. As above,
such fractions may represent the portion of the starch based
polymeric material that is derived from or attributable to (formed
from) the first starch. In an illustrative example, the first
starch can include corn starch, the second starch can include
potato starch, and the third starch can include tapioca starch.
[0143] In various implementations, the film 224 can include a
starch-based polymeric material that is formed from about 15% by
weight to about 25% by weight of a first starch and from about 75%
by weight to about 85% by weight of a second starch. As above, such
fractions may represent the portion of the starch based polymeric
material that is derived from or attributable to (formed from) the
second starch. In an illustrative example, the first starch can
include corn starch and the second starch can include potato starch
or tapioca starch. In another illustrative example, the first
starch can include potato starch and the second starch can include
corn starch or tapioca starch. In an additional illustrative
example, the first starch can include tapioca starch and the second
starch can include corn starch or potato starch.
[0144] In addition to the starch-based polymeric material, the film
224 can also include a polyethylene-containing polymeric material.
In an implementation, the film 224 can include from about 20% by
weight to about 35% by weight of the starch-based polymeric
material and from about 60% by weight to about 75% by weight of the
polyethylene-containing polymeric material. Furthermore, the film
224 can include from about 3% by weight to about 7% by weight of a
compatibilizer, such as a maleic anhydride-based
compatibilizer.
[0145] In implementations where the film 224 includes an amount of
a polyethylene-containing polymeric material and a starch-based
polymeric material formed from a single starch, the film 224 can
have a dart drop impact test value from about 140 g to about 420 g.
Such values may be at any given film thickness, or per mil of film
thickness. Additionally, in implementations where the film 224
includes a polyethylene-containing polymeric material and a
starch-based polymeric material formed from a mixture of starches,
the film 224 can have a dart drop impact test value from about 250
g to about 350 g or from 265 g to about 335 g, where such values
may be for any given film thickness, or per mil of film
thickness.
[0146] In some cases, when the film 224 includes a starch-based
polymeric material formed from a mixture of starches, the film 224
can have a dart drop impact test value that is greater than a dart
drop impact test value of an otherwise similar film but including a
starch-based polymeric material formed from a single one of any of
the starches in the mixture of starches. For example, in addition
to including an amount of a petrochemical-based polymeric material,
such as a polyolefin-based polymeric material, the film 224 can
also include an amount of a carbohydrate-based polymeric material,
such as an amount of a starch-based polymeric material formed from
a mixture of a first starch and a second starch. In these cases,
the film 224 can have a dart drop impact test value that is greater
than a dart drop impact test value of a first article including the
amount of the petrochemical-based polymeric material and a first
starch-based polymeric material formed from a single starch that is
the first starch. The film 224 can also have a dart drop impact
test value that is greater than a dart drop impact test value of a
second article including the amount of the petrochemical-based
polymeric material and a second starch-based polymeric material
formed from a single starch that is the second starch. When the
film 224 includes a starch-based polymeric material formed from a
mixture of the first starch, the second starch, and a third starch,
the film 224 can have a dart drop impact test value that is greater
than a dart drop impact test value of a third article including the
amount of the petrochemical-based polymeric material and a third
starch-based polymeric material formed from a single starch that is
the third starch. Thus, the present films can exhibit synergistic
strength characteristics where a mixture of different starches are
used in forming the carbohydrate-based polymeric material.
Furthermore, it is not necessary that a mixture of starches be used
in forming the carbohydrate-based polymeric material to achieve
increased strength results. For example, two different
carbohydrate-based polymeric materials (one formed from one starch
(e.g., corn), and the other formed from another starch (e.g.,
potato) could similarly be blended with a polyolefin or other
plastic to form a film or other desired article that would exhibit
increased strength as compared to such an article that was formed
from only one or the other of the starches.
[0147] The amount of the first starch included in making the first
article, the amount of the second starch included in making the
second article, and/or the amount of the third starch included in
making the third article can be approximately the same as the
amount of starch used in making the starch-based polymeric material
formed from the mixture of starches included in the film 224. To
illustrate, when the film 224 includes about 25% by weight of the
starch-based polymeric content that is formed from a mixture of
starches, the first article, the second article, and/or the third
article can also be formed from about 25% by weight of the single
starch. Thus, the amount of the petrochemical-based polymeric
content included in the film 224 and the first article, the second
article, and the third article is approximately the same and the
total amount of the starch-based polymeric content included in the
film 224 and the first article, the second article, and the third
article is approximately the same. Additionally, other components
of the film 224, the first article, the second article, and the
third article, such as a compatibilizer, can also be approximately
the same. In these situations, the film 224 differs from the first
article, the second article, and the third article because the
starch-based polymeric source material of the film 224 is formed
from multiple starches, while the starch-based polymeric source
material of the first article, the second article, and the third
article is formed from a single starch.
[0148] Also, the film 224 can have a tensile elongation at break
value in the machine direction from about 600% to about 670% and a
tensile elongation at break value in the transverse direction from
about 625% to about 700%. In particular, the film 224 can have a
tensile elongation at break in the machine direction that is
greater than a tensile elongation at break value in the machine
direction of an article that is formed from one or more
polyolefin-based polymeric materials and free of starch-based
polymeric materials. Furthermore, in implementations where the film
224 is formed from a polyethylene-containing polymeric material and
a starch-based polymeric material formed from a mixture of
starches, the film 224 can have an Elmendorf tear force value in
the machine direction from about 325 g/mil to about 410 g/mil and
an Elmendorf tear force value in the transverse direction from
about 490 g/mil to about 650 g/mil.
[0149] In a particular implementation, the film 224 can be
substantially free of an additive to enhance biodegradation and
include from about 22% by weight to about 27% by weight of a
starch-based polymeric material formed from a mixture of starches.
The film can also include from about 67% by weight to about 73% by
weight of a polyethylene-containing polymeric material. In these
situations, the film 224 can have biodegradation from about 12% to
about 20% according to biomethane potential testing after 32 days.
In addition, after 62 days the film 224 can have biodegradation
from about 26% to about 34% according to biomethane potential
testing. Further, after 91 days, the film 224 can have
biodegradation from about 30% to about 40% according to biomethane
potential testing. As noted above, the biodegradation after a given
relatively short period of time (e.g., within 180 days, within 365
days (1 year), within 2 years, or within 3 years can be greater
than the fraction of the starch-based polymeric material included
in the film, evidencing that the polyethylene is also being
biodegraded, with the starch-based polymeric material. Such results
are remarkable, and particularly advantageous.
[0150] In an embodiment, at least 5%, at least 10%, at least 15%,
at least 20%, at least 25%, at least 30%, at least 35%, at least
40%, at least 45%, at least 50%, at least 55%, at least 60%, at
least 65%, at least 70%, at least 75%, at least 80%, at least 85%,
at least 90%, or even at least 95% of the non-starch-based
polymeric material (e.g., the synthetic petro-chemical based
polymeric material) may biodegrade over a period of at least about
1 year, at least about 2 years, at least about 3 years, or at least
about 5 years when subjected to landfill, composting, and/or marine
conditions (or conditions simulating such). Such biodegradation is
particularly remarkable and advantageous.
[0151] In an implementation, the film 224 can include polymeric
content including one or more petrochemical-based polymeric
materials and one or more carbohydrate-based polymeric materials
formed from one or more carbohydrates where an amount of the
polymeric content that degrades after 91 days measured according to
biomethane potential testing is greater than an amount of the one
or more carbohydrate-based polymeric materials. In a particular
implementation, the film 224 can include (i) a starch-based
polymeric material formed from a first starch and a second starch,
and (ii) a polyolefin-based polymeric material where an amount of
polymeric content that biodegrades after 91 days measured according
to biomethane potential testing is greater than an amount of the
first starch and the second starch source materials used to form
the carbohydrate-based polymeric material and the resulting film.
In some cases, substantially all of the starch-based polymeric
material biodegrades after 91 days as measured according to
biomethane potential testing. Further, an amount of biodegradation
of the film 224 after 91 days measured according to biomethane
potential testing can be from about 5% to about 60% greater than an
amount of the starch-based polymeric material included in the film.
In addition, an amount of polymeric content that biodegrades after
91 days measured according to biomethane potential testing can be
from about 30% by weight to about 50% by weight, even though the
initial starch-based polymeric content of the film was only about
22% to about 27%. Also, an amount of polymeric content that
biodegrades after 62 days measured according to biomethane
potential testing can be from about 25% by weight to about 35% by
weight, which again, is surprising. No inclusion of any
biodegradation enhancing additive is needed to achieve such
results. For example, in various implementations, the film 224 can
be substantially free of a biodegradation enhancing additive, while
in other implementations, the film 224 can include from about 0.5%
by weight to about 2.5% by weight of a biodegradation enhancing
additive. Further Examples show that with increased time, the
amount of biodegradation is even higher, such that in at least some
implementations, substantially the entire film or other article
biodegrades (e.g., biodegradation of at least about 85%, at least
about 90%, or at least about 95% within 180 days, or 200 days, or
365 days (1 year), within 2 years, within 3 years, or other
period).
[0152] Additionally, the film 224 can include from about 20% by
weight to about 40% by weight of one or more carbohydrate-based
polymeric materials or from about 10% by weight to about 50% by
weight of one or more carbohydrate-based polymeric materials. Also,
the film 224 can include from about 65% by weight to about 85% by
weight of one or more petrochemical-based polymeric materials or
from about 60% by weight to about 90% by weight of one or more
petrochemical-based polymeric materials. In some cases, the film
224 can include from about 1% by weight to about 9% by weight of a
compatibilizer or from about 3% by weight to about 7% by weight of
the compatibilizer.
[0153] In a particular implementation, the film 224 can include
from about 20% by weight to about 40% by weight of one or more
starch-based polymeric materials and from about 60% by weight to
about 80% by weight of one or more polyolefin-based polymeric
materials. In an illustrative implementation, the film 224 can
include from about 20% by weight to about 30% by weight of the one
or more starch-based polymeric materials and from about 65% by
weight to about 75% by weight of one or more polyolefin-based
polymeric materials. In some cases, the one or more starch-based
polymeric materials can be formed from a first starch and a second
starch and the source materials from which the one or more
starch-based polymeric materials are formed can include from about
10% by weight to about 25% by weight of a first starch and from
about 55% by weight to about 85% by weight of a second starch. In
other implementations, the source materials from which the one or
more starch-based polymeric materials are formed can include from
about 10% by weight to about 25% by weight of a first starch and
from about 55% by weight to about 85% by weight of a second starch.
In various implementations, the source materials from which the one
or more starch-based polymeric materials are formed can include a
third starch and the third starch can comprise from about 10% by
weight to about 25% by weight of the source materials from which
the one or more starch-based polymeric materials are formed. In an
implementation, such fractions may represent the portion of the
starch based polymeric material that is derived from or
attributable to (formed from) any of the given starches.
[0154] Furthermore, the film 224 can be subjected to compostability
testing under ASTM D-6400 at the time of filing this patent
application. In an implementation, the film 224 can have a
thickness from about 0.035 mm to about 0.050 mm; have a composition
including: from about 22% by weight to about 32% by weight of a
starch-based polymeric material formed from a mixture of starches,
an amount of a polyethylene-based polymeric material from about 65%
by weight to about 75% by weight, an amount of a compatibilizer
from about 3% by weight to about 6% by weight, and be substantially
free of an additive to enhance biodegradation; and when the film
224 is subjected to compostability testing under ASTM D-6400, an
amount of CO.sub.2 emitted in the test chamber after 98 days can be
from about 18% of theoretical maximum CO.sub.2 emissions to about
26% of theoretical maximum CO.sub.2 emissions. In another
implementation, the film 224 can have a thickness from about 0.03
mm to about 0.04 mm; have a composition including: from about 25%
by weight to about 35% by weight of a starch-based polymeric
material formed from a mixture of starches, an amount of a
polyethylene-based polymeric material from about 60% by weight to
about 70% by weight, an amount of a compatibilizer from about 3% by
weight to about 6% by weight, and an amount of an additive to
enhance biodegradation from about 0.5% by weight to about 2% by
weight; and when the film 224 is subjected to compostability
testing under ASTM D-6400, an amount of CO.sub.2 emitted in the
test chamber after 98 days can be from about 29% of theoretical
maximum CO.sub.2 emissions to about 37% of theoretical maximum
CO.sub.2 emissions.
[0155] In an additional implementation, the film 224 can have a
thickness from about 0.035 mm to about 0.050 mm; have a composition
including: from about 22% by weight to about 32% by weight of a
starch-based polymeric material formed from a mixture of starches,
an amount of a polyethylene-based polymeric material from about 65%
by weight to about 75% by weight, an amount of a compatibilizer
from about 3% by weight to about 6% by weight, and be substantially
free of an additive to enhance biodegradation; and when the film
224 is subjected to compostability testing under ASTM D-6400, an
amount of CO.sub.2 emitted in the test chamber after 180 days can
be from about 44% of theoretical maximum CO.sub.2 emissions to
about 52% of theoretical maximum CO.sub.2 emissions. In a further
implementation, the film 224 can have a thickness from about 0.03
mm to about 0.04 mm; have a composition including: from about 25%
by weight to about 35% by weight of a starch-based polymeric
material formed from a mixture of starches, an amount of a
polyethylene-based polymeric material from about 60% by weight to
about 70% by weight, an amount of a compatibilizer from about 3% by
weight to about 6% by weight, and an amount of an additive to
enhance biodegradation from about 0.5% by weight to about 2% by
weight; and when the film 224 is subjected to compostability
testing under ASTM D-6400, an amount of CO.sub.2 emitted in the
test chamber after 180 days can be from about 50% of theoretical
maximum CO.sub.2 emissions to about 60% of theoretical maximum
CO.sub.2 emissions.
[0156] In other implementations, the film 224 can have a thickness
from about 0.03 mm to about 0.04 mm; have a composition including:
from about 25% by weight to about 35% by weight of a starch-based
polymeric material formed from a mixture of starches, an amount of
a polyethylene-based polymeric material from about 10% by weight to
about 20% by weight, an amount of a compostable petrochemical-based
polymeric material from about 45% by weight to about 55% by weight,
an amount of a compatibilizer from about 3% by weight to about 5%
by weight, and include from about 0.5% by weight to about 2% by
weight of an additive to enhance biodegradation; and when the film
224 is subjected to compostability testing under ASTM D-6400, an
amount of CO.sub.2 emitted in the test chamber after 98 days can be
from about 25% of theoretical maximum CO.sub.2 emissions to about
35% of theoretical maximum CO.sub.2 emissions. In a further
implementation, the film 224 can have a thickness from about 0.03
mm to about 0.04 mm; have a composition including: from about 25%
by weight to about 35% by weight of a starch-based polymeric
material formed from a mixture of starches, an amount of a
polyethylene-based polymeric material from about 10% by weight to
about 20% by weight, an amount of a compostable petrochemical-based
polymeric material from about 45% by weight to about 55% by weight,
an amount of a compatibilizer from about 3% by weight to about 5%
by weight, and include from about 0.5% by weight to about 2% by
weight of an additive to enhance biodegradation; and when the film
224 is subjected to compostability testing under ASTM D-6400, an
amount of CO.sub.2 emitted in the test chamber after 180 days can
be from about 70% of theoretical maximum CO.sub.2 emissions to
about 80% of theoretical maximum CO.sub.2 emissions.
[0157] Other architectures can be used to implement the described
functionality, and are intended to be within the scope of this
disclosure.
[0158] The concepts described herein will be further described in
the following examples, which do not limit the scope encompassed by
the claims.
EXAMPLES
Example 1
[0159] A starch-based polymer was formed from 27% tallow glycerin
(99% pure glycerin), and 73% starch. The finished-starch-based
polymer included <1% water. The starch-based polymer was mixed
with LLDPE and anhydride-modified LLDPE in proportions of 25%, 70%,
and 5%, respectively, by weight. Eleven samples were prepared and
blown into films. The temperature settings of the extruder used are
shown in Table 3. B1, B2, B3, B4, and B5 refer to temperature
settings at different locations of the barrel of the extruder and
AD1, D1, and D2 refer to the temperature settings at different
locations in the die section of the extruder.
TABLE-US-00003 TABLE 3 Extruder Temp. B1 B2 B3 B4 B5 AD1 D1 D2 Set
Value 130 140 145 150 160 160 160 160
[0160] The extruder blow settings are shown in Table 4.
TABLE-US-00004 TABLE 4 Extruder Take- Melt Extruder Up Temperature
Pres- Motor Speed Setting sure Screw Setting Blower (meters/ Blow
(.degree. C.) (bar) RMP (Amps) Speed min) Set 148 132 17 32.0 0 7.0
Value (Samples 1-11) Set 147 115 17 32.0 0 7.0 Value (Sample
12)
[0161] 6.5% of the resulting films were formed from glycerin, 18.5%
of each resulting film was formed from starch, 70% of each film was
LLDPE, and 5% of each film was anhydride-modified LLDPE. The films
then were tested using a falling dart impact test according to ASTM
D-1709. The strength test results of these tests are shown in Table
5. Dart strength per mil of thickness can simply be calculated by
dividing the measured dart impact strength (e.g., from ASTM D-1709)
by the thickness of the tested film.
TABLE-US-00005 TABLE 5 Film Thickness Sample No. (Mil) Dart Test
(g) 1 1.535 >387 2 1.50 >387 3 1.50 >387 4 1.50 347 5 1.45
347 6 1.55 387 7 1.55 387 8 1.50 >387 9 1.55 387 10 1.55 >387
11 1.50 >387 12 2.00 227
Example 2
[0162] A starch-based polymer was formed from 27% tallow glycerin
(99% pure glycerin) and 73% starch. The starch-based polymer
included <1% water. The starch-based polymer was mixed with
LLDPE and anhydride-modified LLDPE in proportions of 25%, 70%, and
5%, respectively, by weight. Two samples were prepared and blown
into films. The temperature settings of the extruder used are shown
in Table 6.
TABLE-US-00006 TABLE 6 Extruder Temp. B1 B2 B3 B4 B5 B6 AD1 D1 D2
Set 130 150 155 160 165 165 165 170 170 Value
[0163] The extruder blow settings are shown in Table 7.
TABLE-US-00007 TABLE 7 Extruder Melt Extruder Take-Up Temperature
Motor Speed Setting Pressure Screw Setting Blower (meters/
(.degree. C.) (bar) RPM (Amps) Speed minute) Set 149 121 16.0 35.0
0 6.0 Value
[0164] 6.5% of the resulting films were formed from glycerin, 18.5%
of the resulting films were formed from starch, 70% of each film
was LLDPE, and 5% of each film was anhydride-modified LLDPE. The
films then were tested using a falling dart impact test according
to ASTM D-1709. The strength test results (in grams) of these tests
are shown in Table 8.
TABLE-US-00008 TABLE 8 Film Thickness Sample No. (Mil) Dart Test
(g) 1 1.575 347 2 1.335 362
Example 3
[0165] In order to test the strength characteristics resulting from
various combinations of starch, 17 starch-based polymers were
formed from tallow glycerin (99% pure glycerin) and starch. The
fraction of the starch-based polymer formed from glycerin varied
from 27% to 32%, while the fraction formed from the starch varied
from 68% to 73%. All starch-based polymers exhibited <about 1%
water, and were mixed with LLDPE and anhydride-modified LLDPE in
proportions of 25%, 70%, and 5%, respectively, by weight. The
resulting mixtures were then extruded and blown into films. The
films were then tested using a falling dart drop impact test
according to ASTM D-1709. The combinations of starches tested and
strength test results are shown in Table 9A. The two thickness
values for each sample in Table 9A correspond to the minimum and
maximum measured thickness for each sample (as there was some
variation within each film). As can be seen from the results shown
in Table 9A-9B, samples formed from a mixture of starches have a
dart drop impact test value (in grams) that is greater than the
dart drop impact test value of samples formed from a single starch.
Table 9B shows the calculated percentages in increased strength as
compared to what might be expected (e.g., a weighted strength based
on percentage of each starch in the mixture). The increases in
strength are remarkable, and unexpected.
TABLE-US-00009 TABLE 9A Water Content Sample (Starch-based Starch
Content (%) Dart No. Polymers) Potato Corn Tapioca Thickness (mm)
Test (g) 1 0.58 0 100 0 0.040 0.045 137 2 0.73 100 0 0 0.040 0.045
167 3 0.80 0 100 0 0.040 0.045 167 4 0.93 100 0 0 0.030 0.035 167 5
0.49 0 0 100 0.035 0.040 197 6 0.55 0 0 100 0.030 0.035 212 7 1.03
33.33 33.33 33.33 0.030 0.035 242 8 1.04 20 20 60 0.030 0.035 267 9
0.97 60 20 20 0.025 0.030 252 10 0.93 0 0 100 0.025 0.030 257 11
0.94 20 0 80 0.025 0.030 257 12 1.37 20 80 0 0.025 0.030 257 13
0.95 80 0 20 0.030 0.035 302 14 1.19 20 60 20 0.030 0.035 322 15
0.96 0 80 20 0.025 0.030 277 16 1.05 80 20 0 0.025 0.030 317 17
0.81 0 20 80 0.025 0.030 322
TABLE-US-00010 TABLE 9B Mean Film Dart Percent Thickness Strength
Increase in Dart Sample No. ESR Used (mil) (g/mil) Strength (%) 1
GS-270 1.673 81.9 N/A 2 GS-270 1.673 99.8 N/A 3 GS-300 1.673 99.8
N/A 4 GS-300 1.280 130.5 N/A 5 GS-270 1.476 133.4 N/A 6 GS-300
1.280 165.7 N/A 7 GS-300 1.280 189.1 43.3% 8 GS-300 1.280 208.7
43.4% 9 GS-300 1.083 232.8 77.1% 10 GS-330 1.083 237.4 N/A 11
GS-300 1.083 237.4 49.6% 12 GS-300 1.083 237.4 124.0% 13 GS-300
1.280 236.0 71.6% 14 GS-300 1.280 251.7 111.3% 15 GS-300 1.083
255.8 126.4% 16 GS-300 1.083 292.8 135.4% 17 GS-300 1.083 297.4
95.0%
Example 4
[0166] Using the same protocols as described in Example 3, 11
additional combinations of starches were tested. Specifically, 11
starch-based polymers were formed from 27% tallow glycerin (99%
pure glycerin) and 73% starch. Each starch-based polymer exhibited
<about 1% water, and was mixed with LLDPE and anhydride-modified
LLDPE in proportions of 25%, 70%, and 5%, respectively, by weight.
The resulting mixtures were then extruded and blown into films.
6.5% of each resulting film was formed from the glycerin, 18.5% was
formed from the starch, 70% of each film was LLDPE, and 5% of each
film was anhydride-modified LLDPE. The films were then tested using
a falling dart impact test according to ASTM D-1709. The
combinations of starches tested and strength test results (in
grams) are shown in Table 10. As with the results shown in Tables
9A-9B, the results of Table 10 show that samples formed from a
mixture of starches have dart drop impact test values that are
greater than the dart drop impact test values of samples formed
from a single starch. Such an increase in strength achieved by
using a mixture of different starches in forming the starch-based
polymeric material, from which the film is formed (with the LLDPE)
is surprising an unexpected.
TABLE-US-00011 TABLE 10 Percent Increase Sam- Dart Dart in Dart ple
Starch Content (%) Thickness Test Strength Strength No. Potato Corn
Tapioca (mil) (g) (g/mil) (%) 1 0 100 0 1.535 347 226.1 N/A 2 100 0
0 1.535 362 235.8 N/A 3 0 0 100 1.550 367 236.8 N/A 4 80 20 0 1.550
387 249.7 6.8% 5 0 20 80 1.550 387 249.7 6.4% 6 0 80 20 1.550 387
249.7 9.4% 7 0 10 90 1.550 387 249.7 5.9% 8 33.33 33.33 33.33 1.500
387 258 10.9% 9 80 0 20 1.500 387 258 9.3% 10 10 0 90 1.500 387 258
9.0% 11 0 90 10 1.500 387 258 13.6%
[0167] Although the strength increase values seen in Table 10
differ from those of Example 3 (in Tables 9A-9B), both show a
synergistic strength increase, beyond what would be expected, when
different starches are used in forming the ESR. Various specific
process conditions, such as temperature, blow up ratio, and the
like may affect actual increases achieved.
[0168] FIG. 22 charts dart impact test strength for different
thickness films (0.5 mil, 1 mil, 1.5 mil, 2.0 mils) based on
percentage of ESR in the film. The ESR used in the films formed
shown in FIG. 22 was formed from a blend of starches including 90%
corn starch and 10% potato starch. FIG. 22 shows how the strength
of the film increases with increasing ESR percentage, up to a
maximum strength at about 20% to about 25% ESR. The balance of the
blend included polyethylene and an appropriate compatibilizer, as
described herein.
[0169] FIG. 23 charts dart impact test strength for different
thickness films (from about 0.1 mil up to 2 mils) for films
including 25% carbohydrate-based polymeric material, with the
balance being a small fraction of compatibilizer (e.g., about 5%)
as described herein, and LLDPE (about 70%). FIG. 23 also shows
comparative strength for 100% LLDPE films, which are at all points
lower than for the blend according to the present disclosure. FIG.
23 further shows various other tested reference points for produce
bags (e.g., bags provided to consumers in a supermarket produce
section for holding produce), for various "haul out" bags (e.g.,
grocery and other plastic bags provided for carry out), and for
potato bags (plastic bags used to hold typically 5, 10 or 20 pounds
of potatoes in the produce section of a supermarket).
[0170] FIG. 24 charts dart impact test strength for different
thickness films (from less than 0.5 mil up to about 2 mils) for
various blended films according to the present disclosure, as well
as comparative films (e.g., 100% LLDPE, 100% recycled LLDPE
(rLLDPE). In addition to showing strength characteristics for a
film formed from virgin materials (25% ESR, 70% LLDPE, 5%
compatibilizer (labeled 25% ESR/75% LLDPE), FIG. 24 also shows
strength resulting when such a recycled material (rLDESR) is then
blended with virgin materials (labeled 25% ESR/25% rLDESR/50%
LLDPE), or where recycled LLDPE (rLLDPE) is used in the blend
(labeled 25% ESR/25% rLLDPE/50% LLDPE). The strength results are
improved as compared to use of synthetic petrochemical-based
polymeric materials, as shown, in addition to the previously
described characteristics of increased renewability and
biodegradability.
Example 5
[0171] A starch-based polymer formed from tallow glycerin (99% pure
glycerin) and starch, and exhibiting <about 1% water was mixed
with LLDPE and anhydride-modified LLDPE in proportions of 25%, 70%,
and 5%, respectively, by weight. The starch used in forming the
starch-based polymer was a blend of 90% corn starch and 10% potato
starch, by weight. The mixture of the starch-based polymer and the
LLDPE was extruded and blown into a film. 6.5% of the resulting
film was formed from the glycerin, 18.5% was formed from the two
starches, 70% was LLDPE, and 5% was anhydride-modified LLDPE. For
comparison purposes, a second film containing 100% LLDPE was also
prepared. Using a variety of testing methods a number of strength
characteristics were tested, the results of which are shown in
Table 9. In Table 11, transverse directions is abbreviated (TD) and
machine directions is abbreviated (MD). The results shown in Table
11 indicate that the sample formed from the starch-based polymer
blend has values for some of the strength tests that are greater
than corresponding values for the LLDPE sample.
TABLE-US-00012 TABLE 11 Sample Form Test Method CP14102701 LLDPE
Cardia BL-F Film Thickness Film 1.35 1.35 1.2 (mil) Mass Density
Film or ASTM D-792 1.04 0.92 (SG): Pellets Secant Film ASTM D-882
30 +/- 1 37.7 +/- 2.2 Modulus MD, kpsi Secant Film ASTM D-882 30
+/- 1.3 32.1 +/- 2.4 Modulus TD, kpsi Tensile Film ASTM D-882 4.5
+/- 0.4 4.4 +/- 0.2 2.9 Strength MD Break, kpsi Tensil Strength
Film ASTM D-882 4.3 +/- 0.7 4.7 +/- 1.1 TD Break, kpsi Tensil Film
ASTM D-882 632 +/- 27 571 +/- 25 330 Elongation MD Break, % Tensile
Film ASTM D-882 664 +/- 32 651 +/- 65 Elongation TD Break, %
Elmendorf Film ASTM D-1922 367 +/- 38 254 +/- 41 Tear MD, g/mil
Elmendorf Film ASTM D-1922 568 +/- 70 481 +/- 41 Tear TD, g/mil
Dart Drop Film ASTM D-1709 320 +/- 10 175 +/- 10 200 Impact, g
Barrier: OPV Film cc-25, mic/m.sup.2 2,916 +/- 49 4,346 +/- 130
23.degree. C., 0% RH day-atm O.sub.2 Barrier: MVPV Film
gm/m.sup.2-day 24 +/- 3 14 +/- 0 39.degree. C., 100% RH Optical
Film ASTM D-1746 7 +/- 1 44 +/- 1 Transparency % Heat Seal Film 40
psi, 0.5 sec 1,400 g/in 1,497 g/in Strength Heat Seal Film
130-180.degree. C. 130-180.degree. C. Temperature Range Melt Flow
Rate Pellets ASTM D-1238 0.47 g/10 min 1.0 g/10 min Bio Content
Film or 25% 0% 33% Pellets Water Content Pellets ASTMD-6980 0.35%
0% 0.60%
Example 6
[0172] Seven samples were tested for 32 days to determine
biodegradability characteristics using biomethane potential
testing, to determine the potential for anaerobic biodegradation
based on methanogenesis as a percent of total methanogenesis
potential. The biomethane potential test was intended to replicate
the conditions of a full-scale anaerobic digester (landfill). The
biomethane potential test was conducted at a temperature of about
52.degree. C. using an inoculum having about 55% by weight water
and about 45% by weight organic solids. The positive control sample
was cellulose and the negative control sample was untreated
polyethylene. The results of four samples (referred to as 957, 958,
959, and 960) are shown in FIGS. 3A and 3B and in Table 12.
TABLE-US-00013 TABLE 12 Inoculum Negative Positive 957 958 959 960
Cumulative Gas 729.6 962.5 8184.2 13366.8 2805.7 2995.4 5599.0
Volume (mL) Percent CH.sub.4 (%) 18.4 19.3 35.4 29.2 21.8 0.0 33.6
Volume CH.sub.4 134.2 185.5 2898.2 3904.4 612.4 0.0 1880.7 (mL)
Mass CH.sub.4 (g) 0.10 0.13 2.07 2.79 0.44 0.00 1.34 Percent
CO.sub.2 (%) 49.9 44.0 44.5 43.4 43.2 40.2 45.4 Volume CO.sub.2
364.0 423.3 3639.8 5799.9 1211.8 1204.2 2544.1 (mL) Mass CO.sub.2
(g) 0.72 0.83 7.15 11.39 2.38 2.37 5.00 Sample Mass (g) 1,000 10 10
20.0 20.0 20 20 Theoretical 0.0 8.6 4.2 17.1 17.1 17.1 17.1 Sample
Mass (g) Biodegraded 0.27 0.33 3.50 5.20 0.98 0.65 2.37 Mass (g)
Percent 0.7 76.7 28.8 4.1 2.2 12.3 Biodegraded (%) Adjusted 0.9
100.0 37.5 5.4 2.9 16.0 Percent Biodegraded (%)
[0173] The results of biomethane potential testing for samples 961,
962, and 963 are shown in FIGS. 4A and 4B, and Table 13.
TABLE-US-00014 TABLE 13 Neg- Inoculum ative Positive 961 962 963
Cumulative 729.6 962.5 8184.2 4286.4 5538.9 5796.5 Gas Volume (mL)
Percent CH.sub.4 18.4 19.3 35.4 27.1 31.8 0.0 (%) Volume CH.sub.4
134.2 185.5 2898.2 1161.9 1759.5 0.0 (mL) Mass CH.sub.4 0.10 0.13
2.07 0.83 1.26 0.00 (g) Percent CO.sub.2 49.9 44.0 44.5 42.5 42.7
40.9 (%) Volume CO.sub.2 364.0 423.3 3639.8 1821.0 2363.9 2370.7
(mL) Mass CO.sub.2 0.72 0.83 7.15 3.58 4.64 4.66 (g) Sample Mass
1,000 10 10 20.0 20.0 20 (g) Theoretical 0.0 8.6 4.2 17.1 17.1 17.1
Sample Mass (g) Biodegraded 0.27 0.33 3.50 1.60 2.21 1.27 Mass (g)
Percent 0.7 76.7 7.8 11.3 5.9 Biodegraded (%) Adjusted 0.9 100.0
10.1 14.8 7.6 Percent Biodegraded (%)
[0174] The content and form of the samples tested can be found in
Table 14. The starch-based polymer material was formed from 27%
glycerin (99% pure) and 73% starch, and exhibited <about 1%
water. "Ecoflex" refers to the Ecoflex.RTM. plastic product
available from BASF under that tradename. Bio-B refers to a
degradation enhancing additive available from BiologiQ.
TABLE-US-00015 TABLE 14 Starch- Maleic Based Poly- Anhydride
Biodegradation- Sample Polymer ethylene Ecoflex Modified LLDPE
Additive Enhancing No. (%) (%) (%) (%) (%) Additive Form 957 100 0
0 0 -- Press- outs 958 25 70 5 0 -- Film 959 30 65 5 0 -- Film 960
25 70 5 0 -- Bag 961 25 69 5 1 Enso Restore Film 962 25 69.5 5 0.5
Bio-B Film 963 30 15 50 5 0 -- Film
Example 7
[0175] Seven samples were tested for 91 days to determine
biodegradability characteristics using biomethane potential testing
conducted at a temperature of about 52.degree. C. using an inoculum
having about 55% by weight water and about 45% by weight organic
solids, to determine the potential for anaerobic biodegradation
based on methanogenesis as a percent of total methanogenesis
potential. The positive control sample was cellulose and the
negative control sample was untreated polyethylene. The results of
sample numbers 957, 958, 959, and 960 (compositions shown in Table
14) are shown in FIGS. 5A and 5B and in Table 15.
TABLE-US-00016 TABLE 15 Inoculum Negative Positive 957 958 959 960
Cumulative 811.3 1067.4 8211.9 18074.3 4045.8 5643.8 10915.8 Gas
Volume (mL) Percent CH.sub.4 22.3 23.2 35.5 34.7 32.7 39.4 42.2 (%)
Volume CH.sub.4 180.6 248.1 2914.5 6273.2 1321.2 2224.8 4608.8 (mL)
Mass CH.sub.4 0.13 0.18 2.08 4.48 0.94 1.59 3.29 (g) Percent
CO.sub.2 48.4 43.1 44.4 42.6 42.1 39.7 40.3 (%) Volume CO.sub.2
392.4 460.3 3649.4 7692.5 1703.2 2238.1 4401.5 (mL) Mass CO.sub.2
0.77 0.90 7.17 15.11 3.35 4.40 8.65 (g) Sample 1,000 10 10 20.0
20.0 20 20 Mass (g) Theoretical 1.0 8.6 4.2 17.1 17.1 17.1 17.1
Sample Mass (g) Biodegraded 0.31 0.38 3.52 7.48 1.62 2.39 4.83 Mass
(g) Percent 0.8 76.1 41.9 7.7 12.2 26.4 Biodegraded (%) Adjusted
1.1 100.0 55.0 10.1 16.0 34.7 Percent Biodegraded (%)
[0176] The biomethane potential testing results of sample numbers
961, 962, and 963 (compositions shown in Table 14) are shown in
FIGS. 6A and 6B and in Table 16.
TABLE-US-00017 TABLE 16 Inoculum Negative Positive 961 962 963
Cumulative Gas 811.3 1067.4 8211.9 7385.2 13059.8 11733.3 Volume
(mL) Percent CH.sub.4 (%) 22.3 23.2 35.5 38.6 46.3 45.2 Volume
CH.sub.4 (mL) 180.6 248.1 2914.5 2849.9 6052.3 5302.2 Mass CH.sub.4
(g) 0.13 0.18 2.08 2.04 4.32 3.79 Percent CO.sub.2 (%) 48.4 43.1
44.4 40.9 39.8 39.6 Volume CO.sub.2 (mL) 392.4 460.3 3649.4 3023.8
5197.1 4643.4 Mass CO.sub.2 (g) 0.77 0.90 7.17 5.94 10.21 9.12
Sample Mass (g) 1,000 10 10 20.0 20.0 20 Theoretical 0.0 8.6 4.2
17.1 17.1 17.1 Sample Mass (g) Biodegraded 0.31 0.38 3.52 3.15 6.03
5.33 Mass (g) Percent 0.8 76.1 16.6 33.4 29.3 Biodegraded (%)
Adjusted Percent 1.1 100.0 21.8 43.9 38.5 Biodegraded (%)
Example 8
[0177] A film was tested for 71 days to determine biodegradability
characteristics using biomethane potential testing conducted at a
temperature of about 52.degree. C. using an inoculum having about
55% by weight water and about 45% by weight organic solids, to
determine the potential for anaerobic biodegradation based on
methanogenesis as a percent of total methanogenesis potential. The
positive control sample was cellulose and the negative control
sample was untreated polyethylene. The film contained 25%
starch-based polymer material (with 27% of the starch-based polymer
material being formed from glycerin (99% pure) and 73% of the
starch-based polymer material being formed from starch), and
exhibited <about 1% water). The film included 1% Biosphere.RTM.
additive; 5% maleic anhydride compatibilizer; and 69% modified
LLDPE. The results of the biomethane potential testing of sample
number 983 are shown in FIGS. 7A and 7B and in Table 17.
TABLE-US-00018 TABLE 17 Inoculum Negative Positive 983 Cumulative
Gas Volume 1021.1 1326.5 8225.8 10104.5 (mL) Percent CH.sub.4 (%)
26.3 27.4 35.5 41.7 Volume CH.sub.4 (mL) 268.4 363.3 2922.7 4214.4
Mass CH.sub.4 (g) 0.19 0.26 2.09 3.01 Percent CO.sub.2 (%) 47.6
42.3 44.4 41.9 Volume CO.sub.2 (mL) 185.7 561.2 3654.2 4230.1 Mass
CO.sub.2 (g) 0.95 1.10 7.18 8.31 Sample Mass (g) 1,000 10 10 20.0
Theoretical Sample Mass 0.0 8.6 4.2 17.1 (g) Biodegraded Mass (g)
0.40 0.50 3.52 4.52 Percent Biodegraded (%) 1.1 73.9 24.0 *Adjusted
Percent 1.4 100.0 32.5 Biodegraded (%)
Example 9
[0178] Eight samples (sample numbers 957-963 and 983; compositions
shown in Examples 5 and 7) were tested for 91 days to determine
biodegradability characteristics using biomethane potential testing
conducted at a temperature of about 52.degree. C. using an inoculum
having about 55% by weight water and about 45% by weight organic
solids, to determine the potential for anaerobic biodegradation
based on methanogenesis as a percent of total methanogenesis
potential. The positive control sample was cellulose and the
negative control sample was untreated polyethylene. The results are
shown in Table 18. The results shown in Table 18 indicate that
samples formed from a mixture of a starch-based polymer and a
polyolefin based polymer biodegrades an amount that is greater than
the amount of the starch-based polymer. In some cases, the sample
that biodegraded more than an amount of the starch-based polymer
present was free of a biodegradation enhancing additive. Such
results are surprising, and particularly advantageous.
TABLE-US-00019 TABLE 18 % Degraded Item # 32 Days 42 Days 62 Days
71 Days 91 Days 957 37.50% 48.40% 55.00% 958 5.40% 8.10% 10.10% 959
2.90% 11.30% 16.00% 960 16.00% 30.00% 34.70% 961 10.10% 19.40%
21.80% 962 14.80% 26.40% 43.90% 963 7.60% 28.10% 38.50% 983 19.20%
32.50%
Example 10
[0179] Four samples (sample numbers 100, 200, 300, and 400) were
tested for compostability using the ASTM D-6400 standard at the
time of filing of this patent application. The ASTM D-6400 standard
specifies a phytotoxicity testing procedure, indicates that the
biodegradation of articles is to be measured according to the ASTM
D-5338-11 test, and that an elemental analysis is to utilize Table
3 of 40 C.P.R. Part 503.13. The compositions of the samples and the
biodegradation portion of the compostability test results are shown
in Table 19. The starch-based polymeric material was formed from a
blend of starches including 90% corn starch and 10% potato starch.
The first petrochemical-based polymeric material was a linear
low-density polyethylene produced using a metallocene catalyst. The
compatibilizer for samples 100 and 200 was a Bynel.RTM.
compatibilizer from DuPont.RTM. and the compatibilizer for samples
300 and 400 was an Amplify.TM. compatibilizer from Dow.RTM.. The
biodegradation enhancing additive for samples 100 and 200 was from
Biosphere.RTM. and the biodegradation enhancing additive for sample
300 was from ENSO. The second petrochemical-based polymeric
material was Ecoflex.RTM. from BASF, which is a fossil raw
materials-based plastic that is compostable according to the ASTM
D-6400 standard. The 98 day biodegradability results indicated the
test chamber carbon dioxide measurement as a percentage of a
theoretical maximum amount of carbon dioxide for the sample after
98 days. The 180 day biodegradability results indicated the test
chamber carbon dioxide measurement as a percentage of a theoretical
maximum amount of carbon dioxide after 180 days.
[0180] FIG. 8A shows the results of the biodegradation portion of
the ASTM D-6400 test performed according to ASTM D-5338 for sample
100. FIG. 8B shows the results of the biodegradation portion of the
ASTM D-6400 test performed according to ASTM D-5338 for sample 200.
FIG. 9A shows the results of the biodegradation portion of the ASTM
D-6400 test performed according to ASTM D-5338 for sample 300 and
FIG. 9B shows the results of the biodegradation portion of the ASTM
D-6400 test performed according to ASTM D-5338 for sample 400. The
results of the biodegradation portion of the ASTM D-6400 test
indicate that, after 180 days, an amount of first
petrochemical-based polymeric material in samples 100, 300, and 400
has degraded partially because the amount of carbon dioxide
measured in the test chamber is greater than the percentage of the
starch-based polymeric material included in these samples. Thus, at
least a portion of the remainder of the carbon dioxide emissions is
due to the degradation of the first petrochemical-based polymeric
material. This observation includes sample 400, which is free of a
biodegradation enhancing additive. Such a result is surprising and
advantageous.
[0181] FIG. 10 shows the results of the phytotoxicity portion of
the ASTM D-6400 test for sample 100. FIG. 11 shows the results of
the phytotoxicity portion of the ASTM D-6400 test for sample 200.
FIG. 12 shows the results of the phytotoxicity portion of the ASTM
D-6400 test for sample 300. FIG. 13 shows the results of the
phytotoxicity portion of the ASTM D-6400 test for sample 400.
Passing the phytotoxicity portion of the ASTM D-6400 test indicates
that the linear low density polyethylene included in the samples
was being degraded without the production of harmful
byproducts.
[0182] FIG. 14A shows the results of the elemental analysis portion
of the ASTM D-6400 test based on Table 3 of 40 C.P.R. Part 503.13
for sample 100. FIG. 14B shows the results of the elemental
analysis portion of the ASTM D-6400 test based on Table 3 of 40
C.P.R. Part 503.13 for sample 200. FIG. 15A shows the results of
the elemental analysis portion of the ASTM D-6400 test based on
Table 3 of 40 C.P.R. Part 503.13 for sample 300. FIG. 15B shows the
results of the elemental analysis portion of the ASTM D-6400 test
for sample 400. The results for the elemental analysis portion of
the ASTM D-6400 test based on Table 3 of 40 C.P.R. Part 503.13 also
indicate the absence of harmful byproducts as the samples
degraded.
TABLE-US-00020 TABLE 19 Sample Sample Sample Sample No. 100 No. 200
No. 300 No. 400 Starch-Based Polymeric 30% 30% 40% 25% Material
First Petrochemical-Based 64% 15% 50% 70% Polymeric Material
Compatibilizer 5% 5% 5% 5% Biodegradation Enhancing 1% 1% 5% 0%
Additive Second Petrochemical-Based 0% 49% 0% 0% Polymeric Material
Film Thickness (mm) 0.34 0.34 -- 0.44 98 Day Biodegradability
Results 33% 29% 20% 22% 180 Day Biodegradability 55% 74% 45% 48%
Results
Example 11
[0183] Three samples were tested for 349 days to determine
biodegradability characteristics according to ASTM D-5511. The test
was intended to replicate the conditions of a full-scale anaerobic
digester (landfill). The results of the three samples (referred to
as 1342, 1343, and 1344) are shown in FIG. 16 and in Table 20.
Sample 1342 was formed from 30% ESR (the starch-based polymeric
material), 67% PBAT, and 3% compatibilizer, and had a thickness of
1.1 mil. Sample 1343 was formed from 27.5% ESR, 70% PBAT and 2.5%
compatibilizer, and had a thickness of 1.0 mil. Sample 1344 was
formed from 40% ESR, 56% LLDPE and 4% compatibilizer, and had a
thickness of 1.0 mil.
TABLE-US-00021 TABLE 20 Inoculum Negative Positive 1342 1343 1344
Cumulative Gas 4064.3 4898.8 12330.2 18429.0 20233.7 31171.1 Volume
(mL) Percent CH.sub.4 (%) 43.2 43.6 41.4 48.8 53.7 51.7 Volume
CH.sub.4 1757.0 2135.1 5101.0 8992.6 10865.0 16106.6 (mL) Mass
CH.sub.4 (g) 1.26 1.53 3.64 6.42 7.76 11.5 Percent CO.sub.2 (%)
40.4 37.8 41.9 35.5 35.7 38.0 Volume CO.sub.2 1643.0 1852.9 5160.5
6547.5 7230.7 11838.7 (mL) Mass CO.sub.2 (g) 3.23 3.64 10.14 12.86
14.20 23.25 Sample Mass (g) 10 10 10 20.0 20.0 20 Theoretical 0.0
8.6 4.2 9.8 9.8 13.7 Sample Mass (g) Biodegraded 1.82 2.14 5.50
8.33 9.69 14.97 Mass (g) Percent 3.7 87.1 66.4 80.2 95.8
Biodegraded (%)
[0184] FIG. 16 shows that after 204 days, the negative control
showed 2.5% degradation, the positive control showed 86.5%
degradation, sample 1342 showed 43.3% degradation, sample 1343
showed 53.9% degradation, and sample 1344 showed 77.2% degradation.
At 349 days, the degradation values are as shown in Table 20.
[0185] The biodegradation after 349 days is particularly excellent.
For example, while samples including PBAT (1342 and 1343) show very
good biodegradation, with the percent biodegraded being far greater
than the fraction of the starch-based polymeric material included
in the film, sample 1344 is even more surprising, showing nearly
96% biodegradation (even higher than the positive control), where
the petrochemical-based polymeric material is polyethylene, which
under normal circumstances is not biodegradable (e.g., see the
negative control, in Table 20 which was 100% polyethylene). Such
biodegradation results are remarkable, and particularly
advantageous.
Example 12
[0186] Potato packaging bags made with a blend of 25% ESR, 70%
LLDPE and 5% compatibilizer were tested for anaerobic
biodegradation after 60 days, 107 days, 202 days, 317 days, 439
days, 573 days, and 834 days according to ASTM D-5526. The test was
intended to replicate the conditions of a full-scale anaerobic
digester (landfill). The test was conducted under various
conditions, with an inoculum having about 35%, 45%, and 60% organic
solids with the balance being water. The results for the inoculum
including 35% organic solids (and 65% water) are shown in FIG. 17
and Table 21A. Table 21B shows results for other inoculum values,
and for other samples. The potato bags had a thickness of 1.35
mils. These bags are referred to as sample 1072.
TABLE-US-00022 TABLE 21A 35% 35% 35% 35% 35% 35% 35% Solids @
Solids @ Solids @ Solids @ Solids @ Solids @ Solids @ 60 Days 107
Days 202 Days 317 Days 439 Days 573 Days 834 Days 7.60% 11.80%
24.10% 39.40% 60.50% 71.70% 80.70%
[0187] The potato bags made with 25% ESR, and 70% LLDPE showed a
remarkable 81% biodegradation over 834 days under simulated
landfill conditions. The ESR is homogeneously blended with the
polyethylene, and advantageously results in the long carbon chains
of the polyethylene being broken up, and digested by the same
microorganisms that consume the starch-based polymeric ESR
material. Such results show that the entire bag, including the
polyethylene is being biodegraded into carbon dioxide, methane, and
water. Such results are surprising and particularly
advantageous.
[0188] The testing conducted with 45% organic solids and 60%
organic solids also showed results in which the percent of
biodegradation exceeded the percent of ESR p included in the potato
bag. Tests were also run with similar potato bags including 1% of a
biodegradation enhancing additive (sample 1073), and other similar
potato bags including Ecoflex.RTM. compostable resin, and
metallocene LLDPE (sample 1075).
TABLE-US-00023 TABLE 21B Negative Control Positive Control Percent
Solids 60% 45% 35% 60% 45% 35% Percent 1.20% 0.5 1.5 91.2 91.2 91.4
Biodegraded @ 834 days Sample 1072 Sample 1073 Percent Solids 60%
45% 35% 60% 45% 35% Percent 58.3 67.7 80.7 54.5 67.9 80.3
Biodegraded @ 834 days Sample 1075 Percent Solids 60% 45% 35%
Percent 72.7 83.3 86.1 Biodegraded @ 834 days
Example 13
[0189] Films made with a blend of ESR and LLDPE were tested for
anaerobic biodegradation after 201 days and 370 days according to
ASTM D-5338. The conditions were meant to simulate aerobic
digestion and/or industrial compost conditions. The tested films
are labeled 1345 and 1346 in Table 22 and FIG. 18, which show the
results after 370 days. At 201 days, samples 1345 and 1346
respectively showed adjusted percent biodegraded values of 74.2%
and 72.4%, while the negative control showed -3.3% and the positive
control showed 100%. FIG. 18 plots actual % biodegradation. Sample
1345 included 25% ESR, 72.5% LLDPE, and 2.5% compatibilizer. Sample
1346 included 40% ESR, 56% LLDPE, and 4% compatibilizer.
[0190] Both films had a thickness of 1.0 mil.
TABLE-US-00024 TABLE 22 Inoculum Negative Positive 1345 1346
Cumulative 3168.2 2864.3 10740.0 27603.3 24364.9 Gas Volume (mL)
Percent CO.sub.2 81.4 82.6 83.5 89.3 87.8 (%) Volume CO.sub.2
2577.8 2366.4 8965.3 24638.1 21400.0 (mL) Mass CO.sub.2 5.06 4.65
17.61 48.40 42.04 (g) Sample Mass 1000 10 10 20.0 20.0 (g)
Theoretical 0.0 8.6 4.2 15.0 13.7 Sample Mass (g) Biodegraded 1.38
1.27 4.80 13.20 11.46 Mass (g) Percent -1.3 81.1 78.8 73.5
Biodegraded (%) Adjusted -1.6 100.0 97.2 90.7 Percent Biodegraded
(%)
[0191] The biodegradation after 370 days, especially in sample 1345
is particularly excellent. This sample shows over 97%
biodegradation where the non-biodegradable plastic material is
polyethylene, which under normal circumstances is of course not
biodegradable (e.g., see the negative control, which was 100%
polyethylene). Such biodegradation results are remarkable, and
particularly advantageous.
Example 14
[0192] Films made with a blend of ESR and PBAT were tested for
anaerobic biodegradation after 205 days according to ASTM D-6691,
which is meant to simulate marine conditions. The tested films are
labeled 1439 and 1440 in Table 23 and FIG. 19. At 205 days, samples
1439 and 1440 respectively showed adjusted percent biodegraded
values of 49.6% and 53.6%. Sample 1439 included 30% ESR, 67% PBAT,
and 3% compatibilizer. Sample 1440 included 27% ESR, 70% PBAT, and
2.5% compatibilizer. Sample film 1439 had a thickness of 1.1 mil,
and sample film 1440 had a thickness of 1.0 mil.
TABLE-US-00025 TABLE 23 Inoculum Negative Positive 1439 1440
Cumulative Gas 22.0 25.4 86.7 61.6 65.2 Volume (mL) Percent
CO.sub.2 (%) 91.8 85.4 88.7 91.7 91.3 Volume CO.sub.2 20.2 21.7
76.9 56.4 59.5 (mL) Mass CO.sub.2 (g) 0.040 0.043 0.151 0.111 0.117
Sample Mass (g) 0.080 0.080 0.080 0.080 Theoretical 0.069 0.034
0.039 0.039 Sample Mass (g) Biodegraded 0.011 0.012 0.041 0.030
0.032 Mass (g) Percent 1.2 90.0 49.6 53.6 Biodegraded (%)
[0193] The films showed a greater degree of biodegradation over 205
days relative to the percentage of ESR included in the film. In
other words, the long carbon chains of the polymer are being broken
up, and digested by the same microorganisms that consume the
starch-based polymeric ESR material.
Example 15
[0194] Additional manufactured films were tested for
biodegradability. Table 24 below summarizes the results of such
testing, some of which are described in detail above (e.g.,
Examples 13 and 14). Such testing shows excellent biodegradability
results across a wide range of fractions of carbohydrate-based
polymeric materials, and different petrochemical-based polymeric
materials, under various simulated conditions (e.g., landfills,
composting, marine environments).
TABLE-US-00026 TABLE 24 Sample Sample Sample Sample Sample Sample
Sample MBR MBR MBR MBR MBR MBR 1072 16011801 15121706 16011801
16070601 15120101 15121703 Test Condition Landfill Landfill Compost
Compost Compost Marine Marine ASTM ASTM ASTM ASTM ASTM ASTM ASTM
D-5526 D-5511 D-5338 D-5338 D-5338 D-6691 D-6691 ESR % 25% 40% 25%
40% 40% 30% 27% Compatibilizer + 75% 60% 75% 60% 11% 3% 3% PE %
PBAT % 0% 0% 0% 0% 49% 67% 70% Thickness 1.35 mil 1 mil 1 mil 1 mil
1.5 mil 1 mil 1 mil Days 573 204 201 201 59 205 205 % Degraded
71.1% 77.2% 74.2% 72.4% 96.9% 49.6% 53.6%
IV. Conclusion
[0195] In closing, although the various implementations have been
described in language specific to structural features and/or
methodological acts, it is to be understood that the subject matter
defined in the appended representations is not necessarily limited
to the specific features or acts described. Rather, the specific
features and acts are disclosed as example forms of implementing
the claimed subject matter.
[0196] In closing, it is to be understood that the embodiments of
the inventive features disclosed herein are illustrative of the
principles of the inventive features. Other modifications that may
be employed are within the scope of the inventive features. Thus,
by way of example, but not of limitation, alternative
configurations of the inventive features may be utilized in
accordance with the teachings herein. Accordingly, the inventive
features are not limited to that precisely as shown and
described.
* * * * *