U.S. patent application number 15/246297 was filed with the patent office on 2016-12-15 for synthesis and use of trans-1,3,3,3-tetrafluoropropene/vinylidene fluoride copolymers.
The applicant listed for this patent is HONEYWELL INTERNATIONAL INC.. Invention is credited to Cheryl Cantlon, Changqing Lu, David Nalewajek, Andrew J. Poss, Rajiv R. Singh.
Application Number | 20160362511 15/246297 |
Document ID | / |
Family ID | 50773502 |
Filed Date | 2016-12-15 |
United States Patent
Application |
20160362511 |
Kind Code |
A1 |
Lu; Changqing ; et
al. |
December 15, 2016 |
SYNTHESIS AND USE OF TRANS-1,3,3,3-TETRAFLUOROPROPENE/VINYLIDENE
FLUORIDE COPOLYMERS
Abstract
A copolymer comprising trans-1,3,3,3-tetrafluoropropene units
and vinylidene fluoride units, and methods of making the same. A
method of preventing biofouling on an article of manufacture,
comprising applying such copolymer to the article of manufacture. A
process of preparing a surface having a surface energy of between
about 20 and about 30 mJ/m.sup.2, comprising applying such a
copolymer to a support. A method of preventing accumulation of ice
on an article of manufacture, comprising applying such a copolymer
to an article of manufacture. A method of preparing a polymer,
comprising a step of adding
trans-1,3,3,3-tetrafluoropropene/vinylidene fluoride copolymer as a
polymer processing additive/aid to said polymer.
Inventors: |
Lu; Changqing; (Snyder,
NY) ; Poss; Andrew J.; (Kenmore, NY) ; Singh;
Rajiv R.; (Getzville, NY) ; Nalewajek; David;
(West Seneca, NY) ; Cantlon; Cheryl; (Clarence
Center, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HONEYWELL INTERNATIONAL INC. |
Morris Plains |
NJ |
US |
|
|
Family ID: |
50773502 |
Appl. No.: |
15/246297 |
Filed: |
August 24, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14076624 |
Nov 11, 2013 |
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15246297 |
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61731383 |
Nov 29, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08F 214/22 20130101;
C08F 214/222 20130101; C08L 23/0815 20130101; C09D 5/16 20130101;
C08F 214/22 20130101; C09D 127/16 20130101; C09D 5/1668 20130101;
C08F 214/182 20130101; C08L 27/16 20130101; C08F 216/1408 20130101;
C08F 214/182 20130101; A01N 29/02 20130101; C08F 214/22 20130101;
A01N 31/00 20130101; C08L 23/0815 20130101 |
International
Class: |
C08F 214/22 20060101
C08F214/22; C09D 127/16 20060101 C09D127/16; C09D 5/16 20060101
C09D005/16 |
Claims
1. A process of synthesizing copolymers comprising
trans-1,3,3,3-tetrafluoropropene units and vinylidene fluoride
units, comprising reacting trans-1,3,3,3-tetrafluoropropene
monomers and vinylidene fluoride monomers in a reaction medium.
2. The process of claim 1, wherein said
trans-1,3,3,3-tetrafluoropropene monomers and vinylidene fluoride
monomers are polymerized by aqueous emulsion polymerization.
3. The process of claim 2, wherein the copolymers have a weight
average molecular weight of more than 100,000 Daltons.
4. The process of claim 2, wherein the copolymers have a weight
average molecular weight of more than 400,000 Daltons.
5. The process of claim 4, wherein the
trans-1,3,3,3-tetrafluoropropene monomers and vinylidene fluoride
monomers are additionally reacted with perfluoromethylvinyl ether
monomers and wherein the copolymers additionally comprise
perfluoromethylvinyl ether units.
6. A copolymer comprising trans-1,3,3,3-tetrafluoropropene units
and vinylidene fluoride units.
7. The copolymer of claim 6, having a weight average molecular
weight of more than 100,000 Daltons.
8. The copolymer of claim 6, having a weight average molecular
weight of more than 400,000 Daltons.
9. The copolymer of claim 8, additionally comprising
perfluoromethylvinyl ether units.
10. The copolymer of claim 6, having a surface energy of between
about 20 and about 30 mJ/m.sup.2.
11. The copolymer as in one of claim 10, consisting essentially of
trans-1,3,3,3-tetrafluoropropene units and vinylidene fluoride
units.
12. A method of preventing biofouling on an article of manufacture,
comprising applying the copolymer of claim 9 to the article of
manufacture.
13. A method of preventing biofouling on an article of manufacture,
comprising applying the copolymer of claim 10 to the article of
manufacture.
14. A process of preparing a surface having a surface energy of
between about 20 and about 30 mJ/m.sup.2, comprising applying the
copolymer of claim 9 to a support.
15. A process of preparing a surface having a surface energy of
between about 20 and about 30 mJ/m.sup.2, comprising applying the
copolymer of claim 10 to a support.
16. A method of preventing accumulation of ice on an article of
manufacture, comprising applying the copolymer of claim 9 to the
article of manufacture.
17. A method of preventing accumulation of ice on an article of
manufacture, comprising applying the copolymer of claim 10 to the
article of manufacture.
18. A method of preparing a polymer, comprising a step of adding
trans-1,3,3,3-tetrafluoropropene/vinylidene fluoride copolymer as a
polymer processing additive/aid to said polymer.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is a division of U.S. application
Ser. No. 14/076,624, filed Nov. 11, 2013, which application claims
priority under 35 U.S.C. .sctn.119(e) to U.S. Provisional Patent
Application No. 61/731,383, filed on Nov. 29, 2012, the disclosure
of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present technology relates to
trans-1,3,3,3-tetrafluoropropene/vinylidene fluoride
copolymers.
BACKGROUND OF THE INVENTION
[0003] Over past decades, fluoropolymers have found more and more
applications, ranging from optical devices, corrosion-resistant
coatings, fuel cell membranes, to elastomeric materials. There are
a variety of fluorinated monomers suitable for the preparation of
fluoropolymers, such as tetrafluoroethylene (TFE),
trifluoroethylene (TrFE), chlorotrifluoroethylene (CTFE),
vinylidene fluoride (VDF), vinyl fluoride (VF), hexafluoropropene
(HFP), pentafluoropropene (PFP), tetrafluoropropene (TFP),
trifluoropropene (TrFP), and perfluoroalkylvinyl ether (PAVE), etc.
Among these fluorinated monomers, 1,3,3,3-tetrafluoropropene
(CF.sub.3CH.dbd.CFH; HFO-1234ze) is one of the least studied
monomers. Due to the low reactivity of 1,3,3,3-tetrafluoropropene
monomers with respect to radical polymerization,
1,3,3,3-tetrafluoropropene homopolymer and
1,3,3,3-tetrafluoropropene/tetrafluoroethylene copolymer have only
been made by radiation-induced polymerization at high pressures
between 5,000 and 15,000 atm. See J. Polymer Sci. A: Polym. Chem.
(1973) 11, 1973-1984. This method makes it extremely difficult to
produce 1,3,3,3-tetrafluoropropene homopolymer and copolymers on an
industrial scale. Copolymers of vinylidene fluoride
(CF.sub.2.dbd.CH.sub.2; VDF) with one of several fluorinated
monomers, including 1,3,3,3-tetrafluoropropene, was claimed in GB
Patent No. 1,281,976. However, this patent provided little
information regarding the synthesis of such copolymers.
[0004] There remains a need for new fluoropolymers and new methods
of making such fluoropolymers. The present invention addresses this
need.
[0005] Biofouling is any non-desirable accumulation and growth of
living matter on wetted surfaces. It is a significant, world-wide
problem in almost every industry that relies on water-based
processes. Industries particularly affected by biofouling include
the pulp and paper manufacturing industry and the food industry, as
well as industries connected to underwater construction, ship
building, fish farming and water desalination, to name just a
few.
[0006] One approach to prevent biofouling is the use of non-toxic
coatings that create hydrophobic surfaces to which microorganisms
cannot attach. Fluoropolymers are generally considered useful with
respect to preventing biofouling because of their non-stick and
friction reducing properties.
[0007] Similar to biofouling, the non-desirable accumulation of ice
on surfaces is often a problem in certain industries. One way to
address this problem has been to use non-toxic coatings that create
surfaces that do not allow ice to accumulate.
[0008] Research has shown that the optimal surface energy for
resistance to biofouling in marine environments is always between
20 and 30 mJ/m.sup.2. See J Mater Sci: Mater Med (2006)
17:1057-1062. So far, few fluoropolymers have been shown to produce
this particular surface energy range. For example, on one hand,
poly(tetrafluoroethylene) (PTFE), poly(hexafluoropropylene) (PHFP),
and poly(2,3,3,3-tetrafluoropropene) (poly-1234yf) have a surface
energy below 20 mJ/m.sup.2; on the other hand, the surface energy
of polyvinylidene fluoride (PVDF) and polychlorotrifluoroethylene
(PCTFE) is around 30 mJ/m.sup.2. Only one fluoropolymer,
polytrifluoroethylene (PTrFE), was reported to have a surface
energy within the range of 20 to 30 mJ/m.sup.2.
[0009] There remains a need for improved methods and articles of
manufacture for the prevention of biofouling and accumulation of
ice on surfaces. The present invention addresses this need.
SUMMARY OF THE INVENTION
[0010] The present invention provides a process of synthesizing
copolymers comprising trans-1,3,3,3-tetrafluoropropene units and
vinylidene fluoride units, comprising reacting
trans-1,3,3,3-tetrafluoropropene monomers and vinylidene fluoride
monomers in a reaction medium. In certain embodiments of the
present invention, the trans-1,3,3,3-tetrafluoropropene monomers
and vinylidene fluoride monomers are polymerized by aqueous
emulsion polymerization. In other embodiments of the present
invention, the copolymers have a weight average molecular weight of
more than 100,000 Daltons, or more than 400,000 Daltons. In other
embodiments of the present invention, the
trans-1,3,3,3-tetrafluoropropene monomers and vinylidene fluoride
monomers are additionally reacted with perfluoromethylvinyl ether
monomers and wherein the copolymers additionally comprise
perfluoromethylvinyl ether units.
[0011] The present invention provides a copolymer comprising
trans-1,3,3,3-tetrafluoropropene units and vinylidene fluoride
units. In certain embodiments of the present invention, the
copolymer has a weight average molecular weight of more than
100,000 Daltons, or of more than 400,000 Daltons. In other
embodiments of the present invention, the copolymer additionally
comprising perfluoromethylvinyl ether units. In other embodiments
of the present invention, the copolymer has a surface energy of
between about 20 and about 30 mJ/m.sup.2. In other embodiments of
the present invention, the copolymer consists essentially of
trans-1,3,3,3-tetrafluoropropene units and vinylidene fluoride
units.
[0012] The present invention provides a method of preventing
biofouling on an article of manufacture, comprising applying any
one of the above copolymers to the article of manufacture. The
present invention provides a process of preparing a surface having
a surface energy of between about 20 and about 30 mJ/m.sup.2,
comprising applying any one of the above copolymers to a support.
The present invention provides a method of preventing accumulation
of ice on an article of manufacture, comprising applying any one of
the above copolymers to an article of manufacture.
[0013] The present invention provides a method of preparing a
polymer, comprising a step of adding
trans-1,3,3,3-tetrafluoropropene/vinylidene fluoride copolymer as a
polymer processing additive/aid to said polymer.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The inventors have found that it is possible to synthesize
high molecular weight trans-1,3,3,3-tetrafluoropropene/vinylidene
fluoride copolymers by aqueous emulsion polymerization. The term
1,3,3,3-tetrafluoropropene below refers to
trans-1,3,3,3-tetrafluoropropene. The inventors have also found
that copolymers comprising certain ratios of
1,3,3,3-tetrafluoropropene monomer units and vinylidene fluoride
monomer units have a surface energy of between about 20 and about
30 mJ/m.sup.2 and that the specific surface energy can be
controlled by the specific ratio of the 1,3,3,3-tetrafluoropropene
monomer units and vinylidene fluoride monomer units in the
copolymer. These findings are further set forth in detail in the
Examples below. Surfaces having a surface energy within this range
are resistant to biofouling. See J Mater Sci: Mater Med (2006)
17:1057-1062.
[0015] The present invention provides a process of synthesizing
copolymers comprising 1,3,3,3-tetrafluoropropene units and
vinylidene fluoride units, comprising reacting
1,3,3,3-tetrafluoropropene monomers and vinylidene fluoride
monomers in a reaction medium.
[0016] The copolymerization of 1,3,3,3-tetrafluoropropene and
vinylidene fluoride monomers may be conducted in any aqueous
emulsion solutions, particularly aqueous emulsion solutions that
can be used in conjunction with a free radical polymerization
reaction. Such aqueous emulsion solutions may include, but are not
limited to include, degassed deionized water, buffer compounds
(such as, but not limited to, Na.sub.2HPO.sub.4/NaH.sub.2PO.sub.4),
and an emulsifier (such as, but not limited to,
C.sub.7F.sub.15CO.sub.2NH.sub.4, C.sub.4F.sub.9SO.sub.3K,
CH.sub.3(CH.sub.2).sub.10CON(CH.sub.3)CH.sub.2COONa,
CH.sub.3(CH.sub.2).sub.11OSO.sub.3Na,
C.sub.12H.sub.25C.sub.6H.sub.4SO.sub.3Na,
C.sub.9H.sub.19C.sub.6H.sub.4O(C.sub.2H.sub.4O).sub.10H, or the
like).
[0017] The water soluble radical initiators may include any
compounds that provide free radical building blocks for the
copolymerization of 1,3,3,3-tetrafluoropropene and vinylidene
fluoride monomers. Non-limiting examples of such initiators include
Na.sub.2S.sub.2O.sub.8, .sup.1(.sub.25.sub.2O.sub.8,
(NH.sub.4).sub.25.sub.2O.sub.8, Fe.sub.2(5.sub.2O.sub.8).sub.3,
(NH.sub.4).sub.25.sub.2O.sub.8/Na.sub.2S.sub.2O.sub.5,
(NH.sub.4).sub.25.sub.2O.sub.8/FeSO.sub.4,
(NH.sub.4).sub.25.sub.2O.sub.8/Na.sub.2S.sub.2O.sub.5/FeSO.sub.4,
and the like, as well as combinations thereof
[0018] The polymerization is typically carried out at a
temperature, pressure and length of time sufficient to produce the
desired 1,3,3,3-tetrafluoropropene/vinylidene fluoride copolymer
and may be performed in any reactor known for such purposes, such
as, but not limited to, an autoclave reactor.
[0019] In one embodiment of the present invention, the
polymerization is carried out at a temperature from about
30.degree. C. to about 80.degree. C. and at a pressure from about
50 psi to about 500 psi. The length of the polymerization may be
any length of time to achieve the desired level of polymerization.
In certain non-limiting embodiments, it may be between about 48
hours and about 700 hours. One of skill in the art will appreciate
that such conditions may be modified or varied based upon the
desired conversion rate and the molecular weight of the resulting
1,3,3,3-tetrafluoropropene/vinylidene fluoride copolymers.
[0020] The relative and absolute amounts of
1,3,3,3-tetrafluoropropene monomers and vinylidene fluoride
monomers and the amounts of initiator may be provided to control
the conversion rate of the copolymer produced and/or the molecular
weight range of the copolymer produced. Generally, though not
exclusively, the radical initiator is provided at a concentration
of less than 1.5 weight percent based on the weight of all the
monomers in the copolymerization reaction.
[0021] The initiator may be added into the copolymerization system
multiple times to obtain the desired copolymerization yield.
Generally, though not exclusively, the initiator is added 1 to 5
times into the copolymerization system.
[0022] A third monomer may be introduced to polymerize with
1,3,3,3-tetrafluoropropene monomers and vinylidene fluoride
monomers to produce a terpolymer. Such third monomers include, but
are not limited to, perfluoromethylvinyl ether, hexafluoropropene,
tetrafluoroethylene, chlorotrifluoroethylene, or the like.
[0023] In a preferred embodiment of the present invention, the
copolymerization of HFO-1234ze and VDF is carried out by emulsion
polymerization method. The emulsion polymerization solution
consists of degassed deionized water, the buffer
Na.sub.2HPO.sub.4/NaH.sub.2PO.sub.4, the emulsifier
C.sub.7F.sub.15COO(NH.sub.4), and the oxidizing initiator
(NH.sub.4).sub.25.sub.2O.sub.8. The mixture of HFO-1234ze and VDF
is then transferred into an autoclave reactor at low temperature.
The reducing initiator Na.sub.2S.sub.2O.sub.5 is dissolved in
degassed deionized water and is then pumped into the autoclave
reactor through a syringe pump. The autoclave reactor is slowly
heated up to desired temperature (such as 35.degree. C.) and
maintained at this temperature until the end of the polymerization.
The actual monomer ratio of the copolymer is established by
.sup.19F NMR analysis. The molecular weight of the copolymer is
obtained by GPC measurement. The surface energy of the copolymers
of this invention is obtained by water and diiodomethane contact
angle measurement. All the analytical methods described above are
known in the art and thus not further explained herein.
[0024] In certain embodiments of the present invention, the ratio
of 1,3,3,3-tetrafluoropropene monomer units versus vinylidene
fluoride monomer units in the copolymers of the present invention
is from about 90:10 mol % to about 10:90 mol %. In certain
embodiments of the present invention, the ratio of
1,3,3,3-tetrafluoropropene monomer units versus vinylidene fluoride
monomer units in the copolymers of the present invention is from
about 90:10 mol % to about 70:30 mol %, from about 70:30 mol % to
about 50:50 mol %, from about 50:50 mol % to about 30:70 mol %, and
from about 30:70 mol % to about 10:90 mol %.
[0025] In certain embodiments of the present invention, the
1,3,3,3-tetrafluoropropene monomers and vinylidene fluoride
monomers are polymerized by aqueous emulsion polymerization. In
other embodiments of the present invention, the copolymers
comprising 1,3,3,3-tetrafluoropropene units and vinylidene fluoride
units have a weight average molecular weight of more than 100,000
or more than 400,000 Daltons. Weight average molecular weights are
measured by gel permeation chromatography, which is well known in
the art and thus not further described herein.
[0026] In certain embodiments of the present invention, the
polymerization of the present invention additionally includes
perfluoromethylvinyl ether monomers and the resulting terpolymer
additionally comprises perfluoromethylvinyl ether structural
units.
[0027] The present invention provides a copolymer comprising
1,3,3,3-tetrafluoropropene units and vinylidene fluoride units. In
certain embodiments of the present invention, the copolymer has a
weight average molecular weight of more than 100,000 or more than
400,000 Daltons. In certain embodiments of the present invention,
the above copolymer additionally comprises perfluoromethylvinyl
ether structural units. In certain embodiments of the present
invention, the copolymer consists essentially of
1,3,3,3-tetrafluoropropene units and vinylidene fluoride units. In
other embodiments of the present invention, the copolymer has a
surface energy of between about 20 and about 30 mJ/m.sup.2. In
other embodiments of the present invention, the copolymer has a
surface energy of between about 20 and about 25, or of between
about 25 and about 30 mJ/m.sup.2.
[0028] The present invention provides a method preventing
biofouling on an article of manufacture, comprising applying any of
the above copolymers to the article of manufacture. The present
invention also provides a process of preparing a surface having a
surface energy of between about 20 and about 30 mJ/m.sup.2,
comprising applying any of the above copolymers to a support. In
other embodiments of the present invention, the surface has a
surface energy of between about 20 and about 25 mJ/m.sup.2, or of
between about 25 and about 30 mJ/m.sup.2. The present invention
also provides a process of preventing accumulation of ice on an
article of manufacture, comprising applying any of the above
copolymers to the article of manufacture.
[0029] The surface energy of the copolymers of the present
invention is determined by water and diiodomethane contact angle
measurements, which are methods well known in the art.
[0030] Copolymers comprising 1,3,3,3-tetrafluoropropene and
vinylidene fluoride can be applied to a support or article of
manufacture in any of the many ways generally known in the art. In
a non-limiting example, the copolymer is dissolved as described in
the Examples below and the copolymer solution applied to a support
or article of manufacture and then dried.
[0031] Articles of manufacture within the scope of the present
invention can be any man-made objects prone to biofouling because
they are regularly or permanently exposed to or submerged in water.
Non-limiting examples of such articles of manufacture are any kind
of boats or ships or submarines, machinery or equipment used in or
near water, bridges, offshore drilling platforms, and undersea
cables. In some embodiments of the present invention, the article
of manufacture is selected from the group consisting of a ship, a
boat, a submarine, an undersea cable, an offshore drilling
platform, and a bridge. In even other embodiments of the present
invention, the article of manufacture is at least partly submerged
in water. In even other embodiments of the present invention, the
article of manufacture is at least substantially submerged in
water.
[0032] The following examples further illustrate the invention, but
should not be construed to limit the scope of the invention in any
way.
EXAMPLES
Example 1
[0033] Into 100 mL of degassed deionized water with stirring, 2.133
g of Na.sub.2HPO.sub.47 H.sub.2O, 0.586 g of NaH.sub.2PO.sub.4, and
2.116 g of C.sub.7F.sub.15CO.sub.2NH.sub.4 were added. 0.327 g of
(NH.sub.4).sub.25.sub.2O.sub.8 was then added into the above
aqueous solution with stirring and nitrogen bubbling. The obtained
aqueous solution was immediately transferred into an evacuated 300
mL autoclave reactor through a syringe. The autoclave reactor was
cooled with dry ice, while the aqueous solution inside was slowly
stirred. When the internal temperature decreased to about
-4.degree. C., 122.5 g of 1,3,3,3-tetrafluoropropene and 14.33 g of
vinylidene fluoride were respectively transferred into the
autoclave reactor. At the end of the transfer, the internal
temperature was below about -5.degree. C. The dry ice cooling was
removed. The autoclave reactor was slowly warmed up by air. The
aqueous solution inside was stirred at 300 rpm.
[0034] When the internal temperature increased to about 10.degree.
C., 0.316 g of Na.sub.2S.sub.2O.sub.5 dissolved in 3 mL degassed
deionized water was pumped into the autoclave reactor, followed by
2 mL degassed deionized water to rinse the pumping system. The
autoclave reactor was slowly heated up to 35.degree. C. The initial
internal pressure was 184 psi.
[0035] After 67 hours, the internal pressure decreased to 151 psi.
The heating was stopped. The autoclave reactor was cooled down by
air. The stir rate was decreased to 100 rpm. At room temperature,
0.308 g of (NH.sub.4).sub.25.sub.2O.sub.8 dissolved in 3 ml
degassed deionized water was pumped into the autoclave reactor,
followed by 2 mL degassed deionized water to rinse the pumping
system. 0.306 g of Na.sub.2S.sub.2O.sub.5 dissolved in 3 ml
degassed deionized water was pumped into the autoclave reactor,
followed by 2 mL degassed deionized water to rinse the pumping
system. The stir rate was increased to 300 rpm. The autoclave
reactor was slowly heated to 35.degree. C.
[0036] After another 95 hours, the internal pressure decreased to
132 psi. The heating was stopped. The autoclave reactor was cooled
down by air. The stir rate was decreased to 100 rpm. At room
temperature, the residual pressure was slowly released. The
polymerization mixture was filtered. The small amount of solid
copolymer precipitate was thoroughly washed with deionized water
and dried under vacuum (29 in. Hg) at 35.degree. C. to dryness. The
filtrate (latex) was acidified with conc. hydrochloric acid to
precipitate the copolymer out. The obtained copolymer from latex
was thoroughly washed with deionized water and dried under vacuum
(29 in. Hg) at 35.degree. C. to dryness. The combined copolymers
weighed 22.9 g to give a polymerization yield of 16.7%.
[0037] The actual monomer unit ratio in the copolymer from latex
determined by .sup.19F NMR was 47.5 mol % of
1,3,3,3-tetrafluoropropene and 52.5 mol % of vinylidene fluoride.
The weight average molecular weight of the copolymer measured by
GPC (gel permeation chromatography) was 258,420. The T.sub.g of the
copolymer determined by DSC was 42.degree. C. The copolymer is
soluble in acetone, THF, and ethyl acetate. The copolymer exhibits
the properties of a thermal plastic at temperatures below
42.degree. C.
Example 2
[0038] Into 100 mL of degassed deionized water with stirring, 2.128
g of Na.sub.2HPO.sub.47 H.sub.2O, 0.587 g of NaH.sub.2PO.sub.4, and
2.100 g of C.sub.7F.sub.15CO.sub.2NH.sub.4 were added. 0.315 g of
(NH.sub.4).sub.2S.sub.2O.sub.8 was then added into the above
aqueous solution with stirring and nitrogen bubbling. The obtained
aqueous solution was immediately transferred into an evacuated 300
mL autoclave reactor through a syringe. The autoclave reactor was
cooled with dry ice, while the aqueous solution inside was slowly
stirred. When the internal temperature decreased to about
-3.degree. C., the transfer of a mixture containing
1,3,3,3-tetrafluoropropene (90.1 g) and vinylidene fluoride (36.7
g) was started. At the end of the transfer, the internal
temperature was below about -5.degree. C. The dry ice cooling was
removed. The autoclave reactor was slowly warmed up by air. The
aqueous solution inside was stirred at 300 rpm.
[0039] When the internal temperature increased to about 0.degree.
C., 0.298 g of Na.sub.2S.sub.2O.sub.5 dissolved in 3 mL degassed
deionized water was pumped into the autoclave reactor, followed by
2 mL degassed deionized water to rinse the pumping system. The stir
rate was increased to 500 rpm. The autoclave reactor was slowly
heated up to 35.degree. C. The initial internal pressure was 316
psi.
[0040] After 18 hours, the internal pressure was 238 psi at
35.degree. C. The heating was stopped. The autoclave reactor was
cooled down with dry ice. The stir rate was decreased to 300 rpm.
When the internal temperature decreased to about 0.degree. C.,
0.331 g of (NH.sub.4).sub.2S.sub.2O.sub.8 dissolved in 3 ml
degassed deionized water was pumped into the autoclave reactor,
followed by 2 mL degassed deionized water to rinse the pumping
system. The dry ice cooling was then removed. The autoclave reactor
was slowly warmed up by air. When the internal temperature
increased to about 10.degree. C., 0.312 g of Na.sub.2S.sub.2O.sub.5
dissolved in 3 mL degassed deionized water was pumped into the
autoclave reactor, followed by 2 mL degassed deionized water to
rinse the pumping system. The stir rate was increased to 500 rpm.
The autoclave reactor was slowly heated up to 35.degree. C. The
internal pressure was 219 psi at this time. The copolymerization
was resumed.
[0041] After another 68 hours, the internal pressure decreased to
158 psi at 35.degree. C. The heating was stopped. At room
temperature, the residual pressure was slowly released. The
emulsion mixture was filtered. The filtrate (latex) was acidified
with conc. hydrochloric acid to precipitate the copolymer out. The
copolymer was thoroughly washed with deionized water and dried
under vacuum (28 in. Hg) at 35.degree. C. to dryness. The dry
copolymer weighed 70.3 g to give a polymerization yield of
55.4%.
[0042] The actual monomer unit ratio in the copolymer determined by
.sup.19F NMR was 35.2 mol % of 1,3,3,3-tetrafluoropropene and 64.8
mol % of vinylidene fluoride. The weight average molecular weight
of the copolymer measured by GPC was 384,540. The T.sub.g of the
copolymer determined by DSC was 20.degree. C. The copolymer is
soluble in acetone, THF, and ethyl acetate. The coating film of the
copolymer (by solution casting on aluminum substrate) gave a water
contact angle of 96.6.degree., a diiodomethane contact angle of
73.4.degree., and the corresponding surface energy of 23.3
mJ/m.sup.2, which is the optimal surface energy for biofouling
resistance in marine environment. See J Mater Sci: Mater Med (2006)
17:1057-1062.
Example 3
[0043] Into 100 mL of degassed deionized water with stirring, 2.156
g of Na.sub.2HPO.sub.47 H.sub.2O, 0.589 g of NaH.sub.2PO.sub.4, and
2.168 g of C.sub.7F.sub.15CO.sub.2NH.sub.4 were added. 0.272 g of
(NH.sub.4).sub.25.sub.2O.sub.8 was then added into the above
aqueous solution with stirring and nitrogen bubbling. The obtained
aqueous solution was immediately transferred into an evacuated 300
mL autoclave reactor through a syringe. The autoclave reactor was
cooled with dry ice, while the aqueous solution inside was slowly
stirred. When the internal temperature decreased to about
-4.degree. C., the transfer of a mixture containing
1,3,3,3-tetrafluoropropene (21.7 g) and vinylidene fluoride (57.6
g) was started. At the end of the transfer, the internal
temperature was below about -5.degree. C. The dry ice cooling was
removed. The autoclave reactor was slowly warmed up by air. The
aqueous solution inside was stirred at 300 rpm.
[0044] When the internal temperature increased to about 5.degree.
C., 0.284 g of Na.sub.2S.sub.2O.sub.5 dissolved in 3 mL degassed
deionized water was pumped into the autoclave reactor, followed by
2 mL degassed deionized water to rinse the pumping system. The stir
rate was increased to 500 rpm. The autoclave reactor was slowly
heated towards 35.degree. C. When the internal temperature
increased to about 30.degree. C., an exothermic initiation process
was observed. The internal pressure was 558 psi at about 37.degree.
C. The autoclave reactor was periodically cooled with dry ice to
control the internal temperature between 42.degree. C. and
36.degree. C. After about 3 hours, the heating was resumed to
maintain the internal temperature at 35.degree. C.
[0045] After a total of 40 hours of polymerization, the internal
pressure dropped to 85 psi at 35.degree. C. The heating was then
stopped. The autoclave reactor was cooled down by air. The stir
rate was decreased to 50 rpm. At room temperature, the residual
pressure was slowly released. The white rubbery copolymer
precipitate was taken out and thoroughly washed with deionized
water, and then dried under vacuum (29 in. Hg) at 70.degree. C. to
dryness. The dry copolymer weighed 67.7 g to give a yield of
85.4%.
[0046] The actual monomer unit ratio in the copolymer determined by
.sup.19F NMR was 9.5 mol % of 1,3,3,3-tetrafluoropropene and 90.5
mol % of vinylidene fluoride. The weight average molecular weight
of the copolymer measured by GPC was 448,320. The T.sub.g of the
copolymer determined by DSC was 0.degree. C. The copolymer exhibits
the properties of an elastomer at temperatures above 0.degree.
C.
Example 4
[0047] Into 100 mL of degassed deionized water with stirring, 2.124
g of Na.sub.2HPO.sub.47 H.sub.2O, 0.583 g of NaH.sub.2PO.sub.4, and
2.094 g of C.sub.7F.sub.15CO.sub.2NH.sub.4 were added. 0.318 g of
(NH.sub.4).sub.2S.sub.2O.sub.8 was then added into the above
aqueous solution with stirring and nitrogen bubbling. The obtained
aqueous solution was immediately transferred into an evacuated 300
mL autoclave reactor through a syringe. The autoclave reactor was
then cooled with dry ice and the aqueous solution inside was
stirred at 100 rpm. When the internal temperature decreased to
about -4.degree. C., 46.5 g of 1,3,3,3-tetrafluoropropene, 48.7 g
of perfluoromethylvinyl ether, and 31.0 g of vinylidene fluoride
were respectively transferred into the autoclave reactor. At the
end of the transfer, the internal temperature was below about
-5.degree. C. The dry ice cooling was removed. The autoclave
reactor was slowly warmed up by air. Meanwhile, the stir rate was
increased to 500 rpm.
[0048] When the internal temperature increased to about 12.degree.
C., 0.321 g of Na.sub.2S.sub.2O.sub.5 dissolved in 3 mL degassed
deionized water was pumped into the autoclave reactor, followed by
2 mL degassed deionized water to rinse the pumping system. The
autoclave reactor was slowly heated up to 35.degree. C. The initial
pressure was 270 psi.
[0049] After 19 hours, the internal pressure dropped to 157 psi.
The heating was stopped. The autoclave reactor was cooled down by
air. The stir rate was decreased to 300 rpm. At room temperature,
0.308 g of (NH.sub.4).sub.2S.sub.2O.sub.8 dissolved in 3 ml
degassed deionized water was pumped into the autoclave reactor,
followed by 2 mL degassed deionized water to rinse the pumping
system. 0.311 g of Na.sub.2S.sub.2O.sub.5 dissolved in 3 ml
degassed deionized water was pumped into the autoclave reactor,
followed by 2 mL degassed deionized water to rinse the pumping
system. The stir rate was increased to 500 rpm. The autoclave
reactor was slowly heated up to 35.degree. C. to resume
polymerization. The internal pressure was 134 psi.
[0050] After another 64 hours, the internal pressure dropped to 109
psi at 35.degree. C. The heating was then stopped. The autoclave
reactor was cooled down by air. At room temperature, the residual
pressure was released. The emulsion mixture was filtered. The
filtrate (latex) was acidified with conc. hydrochloric acid to
precipitate the terpolymer out. The obtained terpolymer was
thoroughly washed with deionized water, and then dried under vacuum
(29 in. Hg) at 35.degree. C. to dryness. The dry terpolymer weighed
73.4 g to give a yield of 58.2%.
[0051] The actual monomer unit ratio in the terpolymer determined
by .sup.19F NMR was 21.4 mol % of 1,3,3,3-tetrafluoropropene, 26.1
mol % of perfluoromethylvinyl ether, and 52.5 mol % of vinylidene
fluoride. The weight average molecular weight of the terpolymer
measured by GPC was 388,600. The T.sub.g of the terpolymer
determined by DSC was 0.degree. C. The terpolymer exhibits the
properties of an elastomer at temperatures above 0.degree. C.
Example 5
[0052] Into 100 mL of degassed deionized water with stirring, 2.161
g of Na.sub.2HPO.sub.47 H.sub.2O, 0.584 g of NaH.sub.2PO.sub.4, and
2.093 g of C.sub.7F.sub.15CO.sub.2NH.sub.4 were added. 0.269 g of
(NH.sub.4).sub.2S.sub.2O.sub.8 was then added into the above
aqueous solution with stirring and nitrogen bubbling. The obtained
aqueous solution was immediately transferred into an evacuated 300
mL autoclave reactor through a syringe. The autoclave reactor was
then cooled with dry ice and the aqueous solution inside was slowly
stirred. When the internal temperature decreased to about
-4.degree. C., the transfer of a mixture containing 2.56 g of
1,3,3,3-tetrafluoropropene, 55.0 g of perfluoromethylvinyl ether,
and 44.7 g of vinylidene fluoride into the autoclave reactor was
started. At the end of the transfer, the internal temperature was
below about -5.degree. C. The dry ice cooling was removed. The
autoclave reactor was slowly warmed up by air. The aqueous solution
inside was stirred at 300 rpm.
[0053] When the internal temperature increased to about 15.degree.
C., 0.307 g of Na.sub.2S.sub.2O.sub.5 dissolved in 3 mL degassed
deionized water was pumped into the autoclave reactor, followed by
2 mL degassed deionized water to rinse the pumping system. The
autoclave reactor was slowly heated towards 35.degree. C.;
meanwhile, the stir rate was increased to 500 rpm. When the
internal temperature increased to about 28.degree. C., a slightly
exothermic initiation process was observed. The internal
temperature increased to 37.degree. C. The internal pressure was
439 psi. The autoclave reactor was periodically cooled with dry ice
to control the internal temperature around 35.degree. C. After
about 40 minutes, the heating was re-applied to the autoclave
reactor to maintain the internal temperature at 35.degree. C.
[0054] After a total of 43 hours of polymerization, the internal
pressure dropped to 43 psi at 35.degree. C. The heating was
stopped. The autoclave reactor was cooled down by air. The stir
rate was decreased to 100 rpm. At room temperature, the residual
pressure was released. The clear latex was diluted with 100 mL of
deionized water, and then acidified with conc. hydrochloric acid to
precipitate the terpolymer out. The obtained terpolymer was
thoroughly washed with deionized water, and then dried under vacuum
(29 in. Hg) at 50.degree. C. to dryness. The dry terpolymer weighed
92.1 g to give a yield of 90.1%.
[0055] The actual monomer unit ratio in the terpolymer determined
by .sup.19F NMR was 1.4 mol % of 1,3,3,3-tetrafluoropropene, 34.5
mol % of perfluoromethylvinyl ether, and 64.1 mol % of vinylidene
fluoride. The weight average molecular weight of the terpolymer
measured by GPC included 442,230 (major) and 7,728,300 (minor). The
T.sub.g of the terpolymer determined by DSC was -29.degree. C. This
terpolymer can be used as a fluorinated elastomer at low
temperatures. 1,3,3,3-Tetrafluoropropene monomer units in the
terpolymer could serve as cure sites.
Example 6
Using Trans-1,3,3,3-Tetrafluoropropene/Vinylidene Fluoride
Copolymer as a Polymer Processing Additive
[0056] A Haake counter rotating, intermeshing, conical twin-screw
extruder is used to supply the molten polymer to the die. The melt
temperature of the extrudate is approximately 200.degree. C. The
die consists of a stack of metal block and three removable shims.
The middle shim is used to set the die gap at 0.5 mm. The two outer
shims formed the surface of the die, and are removed for
analysis.
[0057] The polymer used is a well-stabilized butene film grade
LLDPE (ExxonMobil LL-1001.32, available from ExxonMobil) with a
melt index of 1.0 and a density of 0.918. This base resin material
is selected for its overall low level of additives, and the absence
of a polymer processing additive/aid (PPA) in its formulation.
[0058] The polymer processing additive/aid (PPA) to be used is
trans-1,3,3,3-tetrafluoropropene vinylidene fluoride copolymer. The
PPA is added via a 2% masterbatch prepared in the base resin. The
master batch is tumble blended with base resin to achieve a mass
fraction of PPA of 0.1%. Before the test, the equipment is purged
using a commercially available purge compound (HM-10, Heritage
Plastics) comprising a mass fraction of 70% CaCO.sub.3 in 10 mL
LDPE. The metal shims are also cleaned with butanone in a sonic
bath.
[0059] The equipment is purged and cleaned. The base resin is then
added and extruded until constant conditions are obtained. The
shear rate is typically 300 s.sup.-1. The PPA (i.e.,
trans-1,3,3,3-tetrafluoropropene/vinylidene fluoride copolymer) is
then added and extruded until the pressure reaches equilibrium. At
this point, the extruder is stopped, the die is removed,
dismantled, and the shims are collected. This process is usually
done in less than 1 minute and there is very little effect from the
die removal and dismantling on the coating appearance. The process
aid performance is assessed based on percent melt fracture measured
in film samples at regular intervals. Melt fracture is
substantially lower with the processing additive than without.
* * * * *