U.S. patent application number 16/437102 was filed with the patent office on 2019-09-26 for gluten-derived flame retardant materials.
The applicant listed for this patent is International Business Machines Corporation. Invention is credited to SCOTT B. KING, Brandon M. Kobilka, Joseph Kuczynski, Jason T. Wertz.
Application Number | 20190292232 16/437102 |
Document ID | / |
Family ID | 62782257 |
Filed Date | 2019-09-26 |
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United States Patent
Application |
20190292232 |
Kind Code |
A1 |
KING; SCOTT B. ; et
al. |
September 26, 2019 |
Gluten-Derived Flame Retardant Materials
Abstract
A process of forming a gluten-derived flame retardant material
includes forming an amine-functionalized flame retardant molecule
that includes an aryl halide group and a phosphorus moiety. The
process also includes chemically reacting the amine-functionalized
flame retardant molecule with a first gluten protein under
transamidation conditions to bind the phosphorus moiety to
secondary amine of the first gluten protein. The process further
includes initiating a cross-coupling reaction between the aryl
halide group and a terminal amine group of a second gluten protein
to form a gluten-derived flame retardant material.
Inventors: |
KING; SCOTT B.; (Rochester,
MN) ; Kobilka; Brandon M.; (Tucson, AZ) ;
Kuczynski; Joseph; (North Port, FL) ; Wertz; Jason
T.; (Pleasant Valley, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
International Business Machines Corporation |
Armonk |
NY |
US |
|
|
Family ID: |
62782257 |
Appl. No.: |
16/437102 |
Filed: |
June 11, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15404784 |
Jan 12, 2017 |
10377799 |
|
|
16437102 |
|
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C07K 14/415 20130101;
C08L 2201/02 20130101; C09K 21/14 20130101; C08L 101/00
20130101 |
International
Class: |
C07K 14/415 20060101
C07K014/415; C08L 101/00 20060101 C08L101/00; C09K 21/14 20060101
C09K021/14 |
Claims
1. A process of forming a gluten-derived flame retardant material,
the process comprising: forming an amine-functionalized flame
retardant molecule that includes an aryl halide group and a
phosphorus moiety; chemically reacting the amine-functionalized
flame retardant molecule with a first gluten protein under
transamidation conditions to bind the phosphorus moiety to a
secondary amine of the first gluten protein; and initiating a
cross-coupling reaction between the aryl halide group and a
terminal amine group of a second gluten protein to form a
gluten-derived flame retardant material.
2. The process of claim 1, wherein the amine-functionalized flame
retardant molecule includes a halogenated arylamine.
3. The process of claim 2, wherein the phosphorus moiety includes
phosphate group.
4. The process of claim 1, wherein the amine-functionalized flame
retardant molecule includes a halogenated secondary amine.
5. The process of claim 4, wherein the phosphorus moiety includes
phosphate group.
6. The process of claim 1, wherein the phosphorus moiety includes
phosphonate group.
7. The process of claim 1, wherein the cross-coupling reaction
includes a Hartwig-Buchwald cross-coupling reaction.
8. A process of forming a gluten-derived flame retardant material,
the process comprising: forming a mixture that includes--at least
two gluten proteins and an amine-functionalized flame retardant
molecule that includes a phosphorus moiety; initiating a chemical
reaction between a secondary amine of an amino acid component of a
first gluten protein having a terminal carboxylic acid group and
the amine-functionalized flame retardant molecule under amidation
conditions to form a gluten-derived flame retardant material; and
initiating a cross-coupling reaction between the aryl halide group
and a terminal amine group of a second gluten protein to form a
gluten-derived flame retardant material.
9. The process of claim 8, wherein the amine-functionalized flame
retardant molecule includes an arylamine.
10. The process of claim 9, wherein the phosphorus moiety includes
phosphate group.
11. The process of claim 8, wherein the amine-functionalized flame
retardant molecule includes an alkylamine.
12. The process of claim 11, wherein the phosphorus moiety includes
phosphate group.
13. The process of claim 8, wherein the amino acid component of the
gluten protein having the terminal carboxylic acid group includes
glutamic acid.
14. A gluten-derived flame retardant material formed by a process
comprising: forming a mixture that includes at least two gluten
proteins and an amine-functionalized flame retardant molecule that
includes a phosphorus moiety; initiating a chemical reaction
between the amine-functionalized flame retardant molecule and a
secondary amine of a first gluten protein to bind the phosphorus
moiety to the first gluten protein; and initiating a cross-coupling
reaction between the aryl halide group and a terminal amine group
of a second gluten protein to form a gluten-derived flame retardant
material.
15. The gluten-derived flame retardant material of claim 14,
wherein the chemical reaction includes a transamidation reaction
between an internal amide linkage of the first gluten protein and
an amine group of the amine-functionalized flame retardant
molecule.
16. The gluten-derived flame retardant material of claim 14,
wherein the chemical reaction includes an amidation reaction
between an amino acid component of the gluten protein and the
amine-functionalized flame retardant molecule.
17. The gluten-derived flame retardant material of claim 16,
wherein the amino acid component of the gluten protein includes
glutamic acid, aspartic acid, or a combination thereof.
18. The gluten-derived flame retardant material of claim 16,
wherein the amine-functionalized flame retardant molecule includes
an arylamine and a phosphate group or an alkylamine and a phosphate
group.
Description
BACKGROUND
[0001] Plastics are typically derived from a finite and dwindling
supply of petrochemicals, resulting in price fluctuations and
supply chain instability. Replacing non-renewable petroleum-based
polymers with polymers derived from renewable resources may be
desirable. However, there may be limited alternatives to
petroleum-based polymers in certain contexts. To illustrate,
particular plastics performance standards may be specified by a
standards body or by a regulatory agency. In some cases,
alternatives to petroleum-based polymers may be limited as a result
of challenges associated with satisfying particular plastics
performance standards.
SUMMARY
[0002] According to an embodiment, a process of forming a
gluten-derived flame retardant material is disclosed. The process
includes forming an amine-functionalized flame retardant molecule
that includes an aryl halide group and a phosphorus moiety. The
process also includes chemically reacting the amine-functionalized
flame retardant molecule with a first gluten protein under
transamidation conditions to bind the phosphorus moiety to
secondary amine of the first gluten protein. The process further
includes initiating a cross-coupling reaction between the aryl
halide group and a terminal amine group of a second gluten protein
to form a gluten-derived flame retardant material.
[0003] According to another embodiment, a process of forming a
gluten-derived flame retardant material is disclosed. The process
includes forming a mixture that includes--at least two gluten
proteins and an amine-functionalized flame retardant molecule that
includes a phosphorus moiety. The process also includes initiating
a chemical reaction between a secondary amine of an amino acid
component of a first gluten protein having a terminal carboxylic
acid group and the amine-functionalized flame retardant molecule
under amidation conditions to form a gluten-derived flame retardant
material. The process also includes initiating a cross-coupling
reaction between the aryl halide group and a terminal amine group
of a second gluten protein to form a gluten-derived flame retardant
material.
[0004] According to another embodiment, a gluten-derived flame
retardant material is disclosed. The gluten-derived flame retardant
material is formed by a process that includes forming a mixture
that includes at least two gluten proteins and an
amine-functionalized flame retardant molecule that includes a
phosphorus moiety. The process also includes initiating a chemical
reaction between the amine-functionalized flame retardant molecule
and a secondary amine of a first gluten protein to bind the
phosphorus moiety to the first gluten protein. The process also
includes initiating a cross-coupling reaction between the aryl
halide group and a terminal amine group of a second gluten protein
to form a gluten-derived flame retardant material.
[0005] The foregoing and other objects, features, and advantages of
the invention will be apparent from the following more particular
descriptions of exemplary embodiments of the invention as
illustrated in the accompanying drawings wherein like reference
numbers generally represent like parts of exemplary embodiments of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a diagram illustrating examples of gluten-derived
flame retardant materials, according to one embodiment.
[0007] FIG. 2 is a chemical reaction diagram illustrating an
example of a process of forming the first gluten-derived flame
retardant material depicted in FIG. 1, according to one
embodiment.
[0008] FIG. 3 is a chemical reaction diagram illustrating an
example of a process of forming the second gluten-derived flame
retardant material depicted in FIG. 1, according to one
embodiment.
[0009] FIG. 4 is a chemical reaction diagram illustrating an
example of a process of forming the third gluten-derived flame
retardant material depicted in FIG. 1, according to one
embodiment.
[0010] FIGS. 5A and 5B are chemical reaction diagrams illustrating
examples of processes of forming gluten-derived flame retardant
materials from a gluten protein via amidation of terminal
carboxylic acid groups of the gluten protein.
[0011] FIG. 6 is a flow diagram showing a particular embodiment of
a process of forming a gluten-derived flame retardant material from
a gluten protein via transamidation of internal amides of the
gluten protein.
[0012] FIG. 7 is a flow diagram showing a particular embodiment of
a process of forming a gluten-derived flame retardant material from
a gluten protein via amidation of terminal carboxylic acid groups
of the gluten protein.
DETAILED DESCRIPTION
[0013] The present disclosure describes gluten-derived flame
retardant materials and processes of forming gluten-derived flame
retardant materials. The gluten-derived flame retardant materials
of the present disclosure have a phosphorus moiety chemically
bonded to an amino acid component (or multiple components) of a
gluten protein. In some cases, the gluten-derived flame retardant
materials may be formed via transamidation of internal amides of a
gluten protein. In other cases, the gluten-derived flame retardant
materials may be formed via amidation of terminal carboxylic acid
groups of a gluten protein.
[0014] In the present disclosure, a gluten protein (or multiple
gluten proteins) are modified to chemically bind a flame retardant
phosphorus moiety directly to the gluten structure. Gluten is a
protein, and as such, it is composed of sequences of amino acids.
These amino acid sequences are characterized by amide linkages
formed between the amine of one amino acid and the carboxylic acid
group of another amino acid. The amide linkages represent locations
where amine-functionalized flame retardant (AFR) molecules that
include a phosphorus moiety may be inserted into the gluten protein
under transamidation conditions to impart flame retardancy
characteristics. The phosphorus-functionalized gluten proteins or
copolymers of gluten can be blended into a polymer to render the
composite material flame resistant.
[0015] In some cases, one or more of the gluten-derived flame
retardant materials of the present disclosure may be blended with a
polymeric material, and the resulting blend may have flame
retardancy characteristics that satisfy a plastics flammability
standard. As an example, the plastics flammability standard may be
specified by Underwriters Laboratories.RTM. (referred to as "UL"
herein), such as UL 94, entitled "Standard for Safety of
Flammability of Plastic Materials for Parts in Devices and
Appliances testing." The UL 94 standard defines various criteria
that may be used to classify a particular plastic based on a degree
of flame-retardancy. To illustrate, in order for a plastic to be
assigned a "V-1" classification, UL 94 specifies that burning stops
within 30 seconds on a vertical specimen and that drips of
particles are allowed as long as the particles are not inflamed. In
order for the plastic to be assigned a "V-0" classification, UL 94
specifies that burning stops within 10 seconds on a vertical
specimen and that drips of particles are allowed as long as the
particles are not inflamed. Testing may be conducted on a
5-inch.times.0.5-inch (12.7 cm.times.1.27 cm) specimen of a minimum
approved thickness (according to the UL 94 standard). It will be
appreciated that the UL 94 V-1 and V-0 plastics flammability
standards are for example purposes only. Alternative or additional
plastics flammability standard(s) may be applicable in various
contexts.
[0016] Referring to FIG. 1, a diagram 100 illustrates examples of
gluten-derived flame retardant materials having a phosphorus moiety
(or moieties) inserted into a gluten protein under transamidation
conditions. The gluten-derived flame retardant materials depicted
in FIG. 1 may be formed according to the processes illustrated and
further described herein with respect to FIGS. 2-4. In FIG. 1, the
integer i is used to indicate that the number of carbons between
the phenyl group and the phosphorus moiety or between the amide
nitrogen and the phosphorus moiety may be 1 carbon or more than 1
carbon, such as in a range of 1 carbons to 8 carbons.
[0017] FIG. 1 illustrates a first gluten-derived flame retardant
material (identified as "Gluten-Derived Flame Retardant
Material(1)" in FIG. 1), a second gluten-derived flame retardant
material (identified as "Gluten-Derived Flame Retardant
Material(2)" in FIG. 1), and a third gluten-derived flame retardant
material (identified as "Gluten-Derived Flame Retardant
Material(3)" in FIG. 1).
[0018] The first gluten-derived flame retardant material depicted
in FIG. 1 may be formed according to the process described herein
with respect to FIG. 2, where a halogenated arylamine that includes
a phosphorus moiety (e.g., a phosphate group) is used for
transamidation, followed by a cross-coupling reaction.
[0019] The second gluten-derived flame retardant material depicted
in FIG. 1 may be formed according to the process described herein
with respect to FIG. 3, where a halogenated secondary amine that
includes a phosphorus moiety (e.g., a phosphate group, a
phosphonate group, or a phosphinate group) is used for
transamidation, followed by a cross-coupling reaction.
[0020] The third gluten-derived flame retardant material depicted
in FIG. 1 may be formed according to the process described herein
with respect to FIG. 4, where a halogenated secondary amine that
includes a phosphorus moiety (e.g., a phosphonate group, a
phosphinate group, or a phosphine oxide) is used for
transamidation, followed by a cross-coupling reaction.
[0021] Thus, FIG. 1 illustrates examples of gluten-derived flame
retardant materials having a phosphorus moiety chemically bonded to
one or more amino acid components of a gluten protein to impart
flame retardant characteristics. Such phosphorus-functionalized
gluten proteins or copolymers of gluten can be blended into a
polymer to render the composite material flame resistant. In some
cases, the polymeric blend may satisfy a plastics flammability
standard, such as the UL V-0 or V-1 standards, while also
increasing the biorenewable content of the polymeric blend.
[0022] Referring to FIG. 2, a chemical reaction diagram 200
illustrates an example of a process of forming the first
gluten-derived flame retardant material depicted in FIG. 1. FIG. 2
illustrates a first example of a process of inserting a phosphorus
moiety into a gluten protein chain to impart flame retardancy
characteristics. In the particular embodiment depicted in FIG. 2,
the phosphorus moiety (e.g., a phosphate group) is bonded to a
halogenated arylamine. The amine group enables the phosphorus
moiety to be inserted into the gluten protein chain under
transamidation conditions. The transamidation reaction may result
in protein scission, and the halogen group enables subsequent
re-coupling of the protein chains via a Hartwig-Buchwald
cross-coupling reaction.
[0023] The first chemical reaction depicted at the top of FIG. 2
illustrates the formation of a first example of a halogenated
amine-functionalized flame retardant molecule. The halogenated
amine-functionalized flame retardant molecule of FIG. 2 includes an
aryl halide having an amine group and a phosphorus moiety (e.g., a
phosphate group). The second chemical reaction depicted in the
middle of FIG. 2 illustrates that the amine group of the
halogenated amine-functionalized flame retardant molecule enables
the phosphorus moiety to be inserted into the gluten protein chain
under transamidation conditions. After transamidation, the third
chemical reaction depicted at the bottom of FIG. 2 illustrates that
the aryl halide enables a re-coupling of the protein chains via a
cross-coupling reaction between the aryl halide and a terminal
amine group.
[0024] As a prophetic example, the halogenated amine-functionalized
flame retardant molecule illustrated at the top of FIG. 2 may be
formed by a process that includes the four steps depicted above the
chemical reaction arrow. Starting form 2-bromo-4-methylaniline, the
amine may be protected by a tert-butyloxycarbonyl (Boc) protecting
group. This may be followed by the radical bromination of the
benzyl position by N-bromosuccinimide using a radical initiator
such as AIBN or benzoyl peroxide in a solvent such as carbon
tetrachloride. Upon purification, the resulting compound is
subjected to Arbuzov reaction conditions using a trialkyl or
triaryl phosphite (depicted as "P(OR).sub.3" in FIG. 2) and heat to
convert the benzyl bromide group into a benzyl phosphonate.
Examples of R groups may include methyl, ethyl, or phenyl groups
(e.g., inexpensive commercially available groups) but may also
include more complex groups such as furyl or tolyl groups or other
groups such as vinyl, allyl, or longer chain groups. After
purification, the Boc protecting group may be removing using known
chemistry such as acidic conditions.
[0025] In the particular embodiment depicted in FIG. 2, the
transamidation reaction includes a catalytic transamidation
reaction. One set of such transamidation conditions may involve a
transition metal or metalloid complexed catalyst. Another method
involves using an enzyme to perform the transformation, such as
microbial transglutaminase (mTG) or chymotrypsin (ChT).
[0026] The second chemical reaction of FIG. 2 illustrates that
binding the phosphorus-containing molecule to the gluten protein
results in protein chain scission. In FIG. 2, the integer n is used
to represent a number of amide linkages in the gluten protein that
are available for chemical reaction with the halogenated
amine-functionalized flame retardant molecule. After the
transamidation reaction, the integer m is used to represent a
subset of the amide linkages where transamidation occurred. The
integer p is used to represent a subset of amide linkages where
transamidation did not occur.
[0027] The third chemical reaction of FIG. 2 illustrates that the
aryl halide enables re-coupling of the protein chains via a
Hartwig-Buchwald cross-coupling reaction (the coupling of aryl
halides to amines). As a prophetic example, the Hartwig-Buchwald
cross-coupling reaction may include dissolving the products from
the second transamidation reaction in a deoxygenated suitable
solvent such as dioxane. The solvent or reaction mixture may be
deoxygenated by techniques that may include freeze-pump-thaw cycles
or sparging with an inert gas such as nitrogen or argon. A catalyst
such as 1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium
(Pd(dppf)Cl.sub.2), and a base such as sodium tert-butoxide may be
added to the reaction mixture. The reaction mixture may be stirred
at a temperature which may include 100.degree. C. or at reflux, and
may be continued until a sufficient level of coupling reactions are
complete as may be indicated by analysis techniques such as FTIR,
.sup.1H NMR, or gel permeation chromatography (GPC). The product
may be isolated by precipitation and/or extraction, and purified by
centrifugation, crystallization, or chromatography. As noted above,
examples of R groups on the phosphorus moiety may include methyl,
ethyl, or phenyl groups (e.g., inexpensive commercially available
groups) but may also include more complex groups such as furyl or
tolyl groups or other groups such as vinyl, allyl, or longer chain
groups.
[0028] Thus, FIG. 2 illustrates an example of a process of forming
a gluten-derived flame retardant material via a transamidation
reaction followed by a cross-coupling reaction. In some cases, the
gluten-derived flame retardant material formed according to the
process depicted in FIG. 2 may be used as a filler material that is
blended with a polymeric material, such as a polylactic acid (PLA)
material, a polyurethane material, a polycarbonate material, an
acrylonitrile butadiene styrene (ABS) material, a polyester
material, a polyether material, or a combination thereof (among
other alternatives). The addition of the gluten-derived flame
retardant material to the polymeric material may enable the
polymeric material to satisfy a plastics flammability standard
while also increasing the biorenewable content of the polymeric
material.
[0029] Referring to FIG. 3, a chemical reaction diagram 300
illustrates an example of a process of forming the second
gluten-derived flame retardant material depicted in FIG. 1. FIG. 3
illustrates a second example of a process of inserting a phosphorus
moiety into a gluten protein chain to impart flame retardancy
characteristics. In the particular embodiment depicted in FIG. 3,
the amine-functionalized flame retardant molecule includes a
secondary amine that is bonded to an aryl halide and the phosphorus
moiety (e.g., a phosphate group). The amine group enables the
phosphorus moiety be inserted into the gluten protein chain under
transamidation conditions. The transamidation reaction may result
in protein scission, and the halogen group enables subsequent
re-coupling of the protein chains via a Hartwig-Buchwald
cross-coupling reaction.
[0030] The first chemical reaction depicted at the top of FIG. 3
illustrates the formation of a second example of a halogenated
amine-functionalized flame retardant molecule. The halogenated
amine-functionalized flame retardant molecule of FIG. 3 includes a
secondary amine that is bonded to an aryl halide and the phosphorus
moiety (e.g., a phosphate group). The second chemical reaction
depicted in the middle of FIG. 3 illustrates that the amine group
of the halogenated amine-functionalized flame retardant molecule
enables the phosphorus moiety to be inserted into the gluten
protein chain under transamidation conditions. After
transamidation, the third chemical reaction depicted at the bottom
of FIG. 3 illustrates that the aryl halide enables a re-coupling of
the protein chains via a cross-coupling reaction between the aryl
halide and a terminal amine group.
[0031] As a prophetic example, the halogenated amine-functionalized
flame retardant molecule illustrated at the top of FIG. 3 may be
formed by a process that includes reacting dimethyl
(aminomethyl)phosphate and 4-bromobenzyl bromide under nucleophilic
substitution conditions in a suitable solvent which may include
THF, dioxane, acetone, or DMF, and heating to a temperature which
may include a range from 50.degree. C. to reflux. In this example,
both R groups on the phosphorus moiety correspond to methyl groups.
In other cases, different R groups may be bonded to the phosphorus
moiety (e.g., a methyl group and an alternative group). Further, as
noted above, other examples of R groups may include ethyl or phenyl
groups (e.g., inexpensive commercially available groups) but may
also include more complex groups such as furyl or tolyl groups or
other groups such as vinyl, allyl, or longer chain groups. Upon
completion, the reaction may be washed with water and the aqueous
fractions may be extracted with diethyl ether or DCM. The organic
layers may be combined and rinsed with brine and dried over
magnesium sulfate. The solvent may be removed in vacuo and the
product may be purified by recrystallization or chromatography.
[0032] In the particular embodiment depicted in FIG. 3, the
transamidation reaction includes a catalytic transamidation
reaction. One set of such transamidation conditions may involve a
transition metal or metalloid complexed catalyst. Another method
involves using an enzyme to perform the transformation, such as
microbial transglutaminase (mTG) or chymotrypsin (ChT).
[0033] The second chemical reaction of FIG. 3 illustrates that
binding the phosphorus-containing molecule to the gluten protein
results in protein chain scission. In FIG. 3, the integer n is used
to represent a number of amide linkages in the gluten protein that
are available for chemical reaction with the halogenated
amine-functionalized flame retardant molecule. After the
transamidation reaction, the integer m is used to represent a
subset of the amide linkages where transamidation occurred. The
integer p is used to represent a subset of amide linkages where
transamidation did not occur.
[0034] The third chemical reaction of FIG. 3 illustrates that the
aryl halide enables re-coupling of the protein chains via a
Hartwig-Buchwald cross-coupling reaction (the coupling of aryl
halides to amines). The third chemical reaction depicted in FIG. 3
may be performed in a similar manner to the process previously
described herein with respect to FIG. 2.
[0035] Thus, FIG. 3 illustrates an example of a process of forming
a gluten-derived flame retardant material via a transamidation
reaction followed by a cross-coupling reaction. In some cases, the
gluten-derived flame retardant material formed according to the
process depicted in FIG. 3 may be used as a filler material that is
blended with a polymeric material, such as a PLA material, a
polyurethane material, a polycarbonate material, an ABS material, a
polyester material, a polyether material, or a combination thereof
(among other alternatives). The addition of the gluten-derived
flame retardant material to the polymeric material may enable the
polymeric material to satisfy a plastics flammability standard
while also increasing the biorenewable content of the polymeric
material.
[0036] Referring to FIG. 4, a chemical reaction diagram 400
illustrates an example of a process of forming the third
gluten-derived flame retardant material depicted in FIG. 1. FIG. 4
illustrates a third example of a process of inserting a phosphorus
moiety into a gluten protein chain to impart flame retardancy
characteristics. In the particular embodiment depicted in FIG. 4,
the amine-functionalized flame retardant molecule includes a
secondary amine that is bonded to an aryl halide and the phosphorus
moiety (e.g., a phosphonate group). The amine group enables the
phosphorus moiety be inserted into the gluten protein chain under
transamidation conditions. The transamidation reaction may result
in protein scission, and the halogen group enables subsequent
re-coupling of the protein chains via a Hartwig-Buchwald
cross-coupling reaction.
[0037] The first chemical reaction depicted at the top of FIG. 4
illustrates the formation of a third example of a halogenated
amine-functionalized flame retardant molecule. The halogenated
amine-functionalized flame retardant molecule of FIG. 4 includes a
secondary amine that is bonded to an aryl halide and the phosphorus
moiety (e.g., a phosphonate group). In a particular embodiment, the
halogenated amine-functionalized flame retardant molecule of FIG. 4
may be formed in a manner similar to the process previously
described herein with respect to FIG. 3 (starting from
2-aminomethyl dialkyl or diaryl phosphonate). As noted above, in
some cases, both R groups on the phosphorus moiety may correspond
to methyl groups. In other cases, different R groups may be bonded
to the phosphorus moiety (e.g., a methyl group and an alternative
group). Further, as noted above, other examples of R groups may
include ethyl or phenyl groups (e.g., inexpensive commercially
available groups) but may also include more complex groups such as
furyl or tolyl groups or other groups such as vinyl, allyl, or
longer chain groups.
[0038] The second chemical reaction depicted in the middle of FIG.
4 illustrates that the amine group of the halogenated
amine-functionalized flame retardant molecule enables the
phosphorus moiety to be inserted into the gluten protein chain
under transamidation conditions. After transamidation, the third
chemical reaction depicted at the bottom of FIG. 4 illustrates that
the aryl halide enables a re-coupling of the protein chains via a
cross-coupling reaction between the aryl halide and a terminal
amine group.
[0039] In the particular embodiment depicted in FIG. 4, the
transamidation reaction includes a catalytic transamidation
reaction. One set of such transamidation conditions may involve a
transition metal or metalloid complexed catalyst. Another method
involves using an enzyme to perform the transformation, such as
microbial transglutaminase (mTG) or chymotrypsin (ChT).
[0040] The second chemical reaction of FIG. 4 illustrates that
binding the phosphorus-containing molecule to the gluten protein
results in protein chain scission. In FIG. 4, the integer n is used
to represent a number of amide linkages in the gluten protein that
are available for chemical reaction with the halogenated
amine-functionalized flame retardant molecule. After the
transamidation reaction, the integer m is used to represent a
subset of the amide linkages where transamidation occurred. The
integer p is used to represent a subset of amide linkages where
transamidation did not occur.
[0041] The third chemical reaction of FIG. 4 illustrates that the
aryl halide enables re-coupling of the protein chains via a
Hartwig-Buchwald cross-coupling reaction (the coupling of aryl
halides to amines). The third chemical reaction depicted in FIG. 4
may be performed in a similar manner to the process previously
described herein with respect to FIG. 2.
[0042] Thus, FIG. 4 illustrates an example of a process of forming
a gluten-derived flame retardant material via a transamidation
reaction followed by a cross-coupling reaction. In some cases, the
gluten-derived flame retardant material formed according to the
process depicted in FIG. 4 may be used as a filler material that is
blended with a polymeric material, such as a PLA material, a
polyurethane material, a polycarbonate material, an ABS material, a
polyester material, a polyether material, or a combination thereof
(among other alternatives). The addition of the gluten-derived
flame retardant material to the polymeric material may enable the
polymeric material to satisfy a plastics flammability standard
while also increasing the biorenewable content of the polymeric
material.
[0043] Referring to FIGS. 5A and 5B, chemical reaction diagrams 500
and 510 depict examples of processes of forming gluten-derived
flame retardant materials via amidation of terminal carboxylic acid
groups using amine-functionalized flame retardant molecules. Amino
acids that include terminal carboxylic acid groups include glutamic
acid and aspartic acid. In most gluten proteins, glutamic acid
typically makes up approximately 37 percent of the amino acid
content, representing the most common amino acid component.
[0044] In the chemical reaction depicted in FIG. 5A, the
amine-functionalized flame retardant molecule includes an arylamine
that is bonded to a phosphorus moiety (e.g., a phosphate group). In
the particular embodiment depicted in FIG. 5B, the
amine-functionalized flame retardant molecule includes an
alkylamine that is bonded to a phosphorus moiety (e.g., a phosphate
group). As previously described herein, the chain length between
the amide nitrogen and the phosphorus moiety may vary. Accordingly,
it will be appreciated that the molecules depicted in FIGS. 5A and
5B represent illustrative, non-limiting examples. The amine groups
of the amine-functionalized flame retardant molecules of FIGS. 5A
and 5B enable a phosphorus moiety to be inserted into a gluten
protein chain under amidation conditions. As a prophetic example,
terminal amidation may include the use of nanosulfated TiO.sub.2,
neat, at 115.degree. C. This may be accomplished by heating a
mixture of gluten and nanosulfated TiO.sub.2 to 115.degree. C.
under an inert gas such as argon while using an over-head
mechanical stirring apparatus until the reaction is complete. The
nanosulfated TiO.sub.2 may be separated from the gluten by
filtration and/or centrifugation.
[0045] Thus, FIGS. 5A and 5B illustrate examples of processes of
forming gluten-derived flame retardant materials via amidation of
terminal carboxylic acid groups of a gluten protein. In some cases,
the gluten-derived flame retardant materials formed according to
the processes depicted in FIGS. 5A and 5B may be used as a filler
material that is blended with a polymeric material, such as a PLA
material, a polyurethane material, a polycarbonate material, an ABS
material, a polyester material, a polyether material, or a
combination thereof (among other alternatives). The addition of the
gluten-derived flame retardant material(s) to the polymeric
material may enable the polymeric material to satisfy a plastics
flammability standard while also increasing the biorenewable
content of the polymeric material.
[0046] Referring to FIG. 6, a flow diagram illustrates a particular
embodiment of a process 600 of forming a gluten-derived flame
retardant material from a gluten protein via transamidation of
internal amides of the gluten protein. In the particular embodiment
depicted in FIG. 6, the process 600 further includes adding the
gluten-derived flame retardant material to a polymeric material to
form a blend that satisfies a plastics flammability standard.
[0047] The process 600 includes forming an amine-functionalized
flame retardant (AFR) molecule that includes a phosphorus moiety,
at 602. For example, referring to FIG. 2, the halogenated
amine-functionalized flame retardant molecule includes an aryl
halide having an amine group and a phosphorus moiety (e.g., a
phosphate group). As another example, referring to FIG. 3, the
halogenated amine-functionalized flame retardant molecule of FIG. 3
includes a secondary amine that is bonded to an aryl halide and the
phosphorus moiety (e.g., a phosphate group). As a further example,
referring to FIG. 4, the amine-functionalized flame retardant
molecule includes a secondary amine that is bonded to an aryl
halide and the phosphorus moiety (e.g., a phosphonate group).
[0048] The process 600 includes chemically reacting the AFR
molecule with a gluten protein under transamidation conditions to
impart flame retardancy characteristics to the gluten protein, at
604. For example, referring to FIGS. 2-4, the amine groups of the
halogenated amine-functionalized flame retardant molecules enable a
phosphorus moiety to be inserted into the gluten protein chain
under transamidation conditions.
[0049] In the particular embodiment depicted in FIG. 6, the process
600 includes re-coupling protein chains via a Hartwig-Buchwald
cross-coupling reaction, at 606. For example, referring to FIGS.
2-4, after the transamidation reaction, the aryl halide enables a
re-coupling of the protein chains via a cross-coupling reaction
between the aryl halide and a terminal amine group.
[0050] In the particular embodiment depicted in FIG. 6, the process
600 also includes adding the gluten-derived flame retardant
material to a polymeric material to form a blend, at 608. The
addition of the gluten-derived flame retardant material may enable
the blend to satisfy a plastics flammability standard. For example,
the gluten-derived flame retardant material(s) of the present
disclosure may be used as a filler material that is blended with a
polymeric material, such as a PLA material, a polyurethane
material, a polycarbonate material, an ABS material, a polyester
material, a polyether material, or a combination thereof (among
other alternatives). The addition of the gluten-derived flame
retardant material to the polymeric material may enable the
polymeric material to satisfy a plastics flammability standard
(e.g., the UL V-0 or V-1 standards) while also increasing the
biorenewable content of the polymeric material.
[0051] Thus, FIG. 6 illustrates an example of a process of forming
a gluten-derived flame retardant material from a gluten protein via
transamidation of internal amides of the gluten protein. FIG. 6
further illustrates that the gluten-derived flame retardant
material(s) may be blended with a polymeric material to form a
blend that satisfies a plastics flammability standard while also
increasing the biorenewable content of the polymeric material.
[0052] Referring to FIG. 7, a flow diagram illustrates a particular
embodiment of a process 700 of forming a gluten-derived flame
retardant material from a gluten protein via amidation of terminal
carboxylic acid groups of the gluten protein. In the particular
embodiment depicted in FIG. 7, the process 700 further includes
adding the gluten-derived flame retardant material to a polymeric
material to form a blend that satisfies a plastics flammability
standard.
[0053] The process 700 includes forming an amine-functionalized
flame retardant (AFR) molecule that includes a phosphorus moiety,
at 702. The process 700 includes chemically reacting the AFR
molecule with a gluten protein under terminal amidation conditions
to impart flame retardancy characteristics to the gluten protein,
at 704. For example, referring to FIG. 5A, the AFR molecule
includes an arylamine bonded to a phosphorus moiety (e.g., a
phosphate group), and the chemical reaction results in amidation of
the terminal carboxylic acid group (e.g., of the terminal glutamic
acid amino acid component of the gluten protein and/or the side
chains of glutamic/aspartic acid components). As another example,
referring to FIG. 5B, the AFR molecule includes an alkylamine
bonded to a phosphorus moiety (e.g., a phosphate group), and the
chemical reaction results in amidation of the terminal carboxylic
acid group (e.g., of the glutamic acid amino acid component of the
gluten protein).
[0054] In the particular embodiment depicted in FIG. 7, the process
700 also includes adding the gluten-derived flame retardant
material to a polymeric material to form a blend, at 706. The
addition of the gluten-derived flame retardant material may enable
the blend to satisfy a plastics flammability standard. For example,
the gluten-derived flame retardant material(s) of the present
disclosure may be used as a filler material that is blended with a
polymeric material, such as a PLA material, a polyurethane
material, a polycarbonate material, an ABS material, a polyester
material, a polyether material, or a combination thereof (among
other alternatives). The addition of the gluten-derived flame
retardant material to the polymeric material may enable the
polymeric material to satisfy a plastics flammability standard
(e.g., the UL V-0 or V-1 standards) while also increasing the
biorenewable content of the polymeric material.
[0055] Thus, FIG. 7 illustrates an example of a process of forming
a gluten-derived flame retardant material from a gluten protein via
amidation of terminal carboxylic acid groups of the gluten protein.
FIG. 7 further illustrates that the gluten-derived flame retardant
material(s) may be blended with a polymeric material to form a
blend that satisfies a plastics flammability standard while also
increasing the biorenewable content of the polymeric material.
[0056] It will be understood from the foregoing description that
modifications and changes may be made in various embodiments of the
present invention without departing from its true spirit. The
descriptions in this specification are for purposes of illustration
only and are not to be construed in a limiting sense. The scope of
the present invention is limited only by the language of the
following claims.
* * * * *