WO2011008381A1

WO2011008381A1 - Fluoropolymers having diacrylate ends

Info

Publication number: WO2011008381A1
Application number: PCT/US2010/038102
Authority: WO
Inventors: Ming-Hong Hung; Bruno Ameduri
Original assignee: Dupont Performance Elastomers L.L.C.; Le Centre National De La Recherche Scientifique; Kostov, Georgi
Priority date: 2009-07-16
Filing date: 2010-06-10
Publication date: 2011-01-20
Also published as: US20110015358A1; JP2012533646A; US8575300B2; US8394905B2; CN102471411A; EP2454294A1; EP2454294B1; JP5513614B2; US20130072635A1

Abstract

Disclosed herein is a telechelic diacrylate fluoropolymer and a process for manufacture of the fluoropolymer. The diacrylate copolymer is of formula CH₂=CR'COO-(CH₂)_n-R-(CH₂)_n-OOCCR'=CH₂, wherein R is selected from the group consisting of i) an oligomer comprising copolymerized units of vinylidene fluoride and perfluoro(methyl vinyl ether), ii) an oligomer comprising copolymerized units of vinylidene fluoride and hexafluoropropylene, iii) an oligomer comprising copolymerized units of tetrafluoroethylene and perfluoro(methyl vinyl ether), and iv) an oligomer comprising copolymerized units of tetrafluoroethylene and a hydrocarbon olefin, R' is H or -CH₃, n is 1-4 and wherein said oligomer has a number average molecular weight of 1000 to 25,000 daltons.

Description

FLUOROPOLYMERS HAVING DfACRYLATE ENDS FjELP _..OF THE INVENTION

This invention relates to diacrylate copolymers of formula

CH2=CR^'COO-(CH2)n-R-(CH₂)r,-OOCCR^I=CH2, wherein R is selected from the group consisting of i) an oligomer comprising co polymerized units of vinyliciene fluoride and perfluoro(methyl vinyl ether), ii) an oligomer comprising copolyrnerized units of vinyiidene fluoride and

hexafluoro propylene, iii) an oligomer comprising copolyrnerized units of tetrafluoroethylene and perfluoro(methyl vinyi ether), and iv) an oligomer comprising copolyrnerized units of tetrafluoroethylene and a hydrocarbon olefin, R' is H or -CHs, n is 1-4, and wherein said oligomer has a number average molecular weight of 1000 to 25,000 daltoπs.

BACKGROUND. OF THE INVENTION

Difυnctional low molecular weight (number average molecular weight between 1000 and 25,000 daitons) copolymers of vinyfidene fluoride (VF₂) with perfluoro(methyl vinyi ether) (PMVE) and dϊfunctionat copolymers of tetrafluoroethylene (TFE) with PMVE have been disclosed in US 20090105435 A1. A functional group is located at each end of the copolymer main chain (sometimes referred to as "telechelic"). Functional groups disclosed include iodine, ally!, hydroxy!, carboxy! and nitrile. It would be desirable to have low molecular weight fluoropolymers of the type disclosed in US 20090105435 A1 wherein each end of the main polymer chain has an acrylate or methactyiate group. Such fluoropolyrners could be used as intermediates in the synthesis of other fluoropolyrners and could also be vulcanized to form tough coatings, seals, o-rings, gaskets etc. The present invention is both 1} a tefecheiϊc dϊacryiate low molecular weight fluoropolymer and aiso 2} a process for the manufacture of such a copolymer.

Accordingly an aspect of the present invention is a teiechelic diacrylate copolymer of formula CH2=CR^'COO-(CH2)n~R-{CH₂)n- OOCCR'-CH2, wherein R' is H or -CH₃, n is 1-4 and R is an oligomer having a number average molecular weight of 1000 to 25,000 daitoπs, said oligomer selected from the group consisting of i) an oligomer comprising copolymerized units of vϊnyiidene fluoride and ρerf!uoro(methyl vinyl ether), ii) an oligomer comprising copofymerized units of vinylidene fluoride and hexafluoropropylene, iii) an oligomer comprising

copolymerized units of tetrafluoroethylene and perfiuoro(rnethy! vinyl ether), and ϊv) an oligomer comprising copolymerSzed units of

tetrafluoroethylene and a hydrocarbon olefin.

Another aspect of the Invention is a process for the manufacture of a teiechelic diacryiate copolymer, said process comprising;

A) providing a diol of formula HO-(CH2)_π-R-(CH2)_ri-OH, wherein n is 1-4 and R is an oligomer having a number average molecular weight of

1000 to 25,000 daltons, said oligomer selected from the group consisting of i) an oligomer comprising copolymerized units of vinylidene fluoride and perfluoro(methy[ vinyl ether), ii) an oligomer comprising copolymerized units of vinylidene fluoride and hexafluoropropylene, iii) an oligomer comprising copolymerized units of tetrafluoroethylene and

perfJuoro(methyl vinyl ether), and Iv) an oligomer comprising

copofymerized units of tetrafluoroethylene and a hydrocarbon olefin; and

B) reacting said diol with CH^-CROOX, wherein X is a halide and R¹ is H Or -CH₃, to form a diacrylate copolymer of formula CH₂=CROOO-

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to tow molecular weight, telecheϋc diacrylate fluoropoiyrners and a process for the manufacture of said polymers. By the term "diacrylate" is meant that the fluoropoiyrners contain either two acryiate groups or two meihacryiate groups per polymer chain. The acryiate or methacrylate groups are located at both ends of the main polymer chains. By "main chain" is meant the longest chain of copolymerized monomer units, Le. not side chains or branches.

The diacrylate fluoropoiyrners of this invention have the formula CH2=CR^>COO-lCH₂)_π-R-{CH₂)_n-OOCCR^'=CH_2l wherein R" is H or -CH₃, n is 1-4 (preferably 2 or 3) and R is an oligomer having a number average molecular weight of 1000 to 25,000 daitons, preferably 1200 to 12,000 daltons, most preferably 1500 to 5000 daltons. Oligomer, R, is selected from the group consisting of ϊ} an oligomer comprising copoiymerized units of vinylidene fluoride and perfiuoro(methyl vinyi ether), ii) an oligomer comprising copoiymerized units of vinylidene fluoride and

hexafluoropropylene, iii} an oligomer comprising copoiymerized units of tetrafluoroethyiene and ρerfluoro(rnethyi vinyl ether), and iv) an oligomer comprising copoiymerized units of tetrafluoroethyiene and a hydrocarbon oiefin. Hydrocarbon olefins include ethylene (E) and propylene (P), Optionally, oligomer, R, may further comprise at least one additional comonomer, different from the other two comonomers. Examples of such additional comonomers include, but are not limited to vinylidene fluoride (VF?), hexafluoropropylene (HFP), tetrafluoroethyiene (TFE) and perfluoro{methyl vinyi ether) (PMVE),

Specific examples of oligomers that may be employed in the fluoropoiyrners of the invention (and the diols used to make them) include, but are not limited to TFE/PMVE, VF₂ZPMVE, VF₂/TFE/PMVE₅

TFE/PMVE/E, VF₂ZHFP, VF₂ZHFPZTFE, TFEZP and TFEZPZVF₂. Diacryϊate fiuoropoiymers of the Invention may be made by a process comprising A) providing a dioi of formula HO-(CH₂ VR-(CH₂J_n- OH₁ wherein n and R are defined above; and B) reacting said diol with CH₂=CR¹COX, wherein X and R' are defined above, to form a tefechelic diacrylate copolymer of formula C^=CR¹COO-(CH₂VR-(CH₂V

OOCCR'=CH_?.

Diols of formula HO-(CH₂VR-(CH₂)_H-OH may be made from a multi-step process beginning with the corresponding α, to-dϊiodo oligomers of formula l-R-l prepared generally as described in U.S. 20090105435 Al . The diiodo oligomers may be ethyieneaied (or ailylated) by reaction, in the presence of a radical initiator, with ethylene {or ally! alcohol, followed by the selective reduction of the iodine atoms). The resulting oligomers may then be hydrolyzed to form the dials.

Fiuoropolymers of this invention are useful in forming crosslinked fluoropoiymor networks having good flexibility, chemical resistance and thermal properties.

EXAMPLES TEST METHODS

Number average molecular weight (Mn) was determined by size exclusion chromatography (SEC). Samples were dissolved in THF.

Analyses were performed with a Spectra-Physics chromatograph equipped with two PLgei 5μm Mlxed-C columns from Polymer

Laboratories and a Spectra Physics SP8430 Refractive Index (Ri) and UV defector. Tetrahydrofuran (THF) was used as eluent, with a flow rate of 0.8 mL min^"1. Standards were monodispersed poly(styrene) (PS) or polymethylmethacrylate), purchased from Polymer Laboratories or other vendors.

Fluofopoiymer and oligomer compositions and microstruclures were determined by ¹"F and ¹H NMR. The NMR spectra were recorded on a Bruker AC 200, AC, 250 and AC 400 (200, 250 and 400 MHz)

instruments, using deulerated acetone as solvent and tetramethylsiiane (TMS) (or CFCb) as the references for ¹H (or ^|CfF) nuclei, Coupling constants and chemical shifts are given in Hz and ppm, respectively. The experimental conditions for ¹H (or ¹⁹F) NiVIR spectra were the following: flip angle 90° (or 30°), acquisition lime 4.5 s (or 0.7 s), pulse delay 2 s (or 5 s), number of scans 16 (or 64), and a pulse width of 5 μs for ¹⁹F NMR. Example 1

In this example, a flυoropolymer of the invention, CH2-CHCOO- (CH₂)_IrR-(CH₂)P-OOCCH=CH₂. wherein R is po!y(vϊnylideπe fiuoride-co- perfluorofmethyl vinyl ether) [i.e. poty(VF₂-co-PMVE)3, was made by the process of the invention.

The dioi oligomer employed in the fluoropolymer manufacturing process was made from a multi-step process, beginning with a telechelic diiodo oligomer of formula [-(VF_?-co-PMVE)-L The latter was made by the process disclosed in U.S. 20090105435 A1. This diiodo oligomer contained 73.2 mol% VF2 and 26.8 mol% PMVE and had a number average molecular weight of 2450 daltons.

Ethylenalioπ of the diiodo oligomer:

A 160 mL Hastelloy (HC-276) autoclave, equipped with inlet and outlet valves, a manometer and a rupture disc, was degassed and pressurized with 30 bar of nitrogen Io check for leaks. Then, a 0.5 mm Hg vacuum was operated for 5 minutes (min.) and subsequently an argon atmosphere was applied. Such a procedure of autoclave degassing was repeated five times. Under vacuum, 5,0 g (2.87 x 10^'2 moles) of t- butylperoxypivalate (TBPPi), 50 mL of f-butanoi and 100.0 g (0.077 moles) of the above-described telechelic diiodo oligomer were transferred into the autoclave. 6.0 g of ethylene (0.214 moles) was introduced into the autoclave. Then, the autoclave was progressively heated to 75°C. An exotherm was observed of about 10^DC and an increase of pressure from 15 bars up to 18 bars, foitowed by a drop of pressure to 14 bars over 16 hours. After reaction, the autoclave was placed in an ice bath for about 80 minutes and 0,5 g of unreacted ethylene was slowly released. After opening the autoclave, the reaction mixture was dissolved in 100 mi of butanone and washed with distilled water (2 x 100 mi), Na₂S₂O₅ solution (100 m!) and brine (100 mi) respectively in a separating funnel. Then, the organic phase was dried over MgSO₄ and filtered through sintered glass (G4). The organic solvent was removed by a rotary vacuum evaporator at 40⁰C, reducing pressure to 10 mm Hg. The resulting slightly yellow viscous liquid was dried at 4QX under 0.01 mbar vacuum to constant weight. The yield of the reaction was 91 %. The product was analyzed by ¹H NMR and ^'yF NMR spectroscopy. An absence of the signal

corresponding to the terminal -CF₂I (approximately -39 ppm} indicated quantitative conversion to the ethyleneated oligomer.

Hydrolysis of Ethylenated Copolymer to the Telechelic Diol:

To a 250 ml two-neck round-bottom flask equipped with a reflux condenser and magnetic stirrer was introduced 61.6 g (0.044 moles) of ethylenated product synthesized above and 80.4 g (1.1 moles) of DMF. Then, the mixture was purged with nitrogen for 20 min. and 4.0 g of water was added through a septum. The reaction was heated to 120⁰C and stirred overnight. After 14 hours (hrs.), the crude product (reaction mixture) was cooled to room temperature and a mixture of H^SO₄ (25 g) in methanol (70 g) was added dropwise. The reaction was kept at room temperature for 24 hrs. Then, the reaction mixture was washed with distilled water (3x 100 ml) and ethyl acetate (200 ml) in a separating funnel. The organic phase was dried over MgSO₄ and filtered through sintered glass (G4). The ethyl acetate and traces of DMF were removed by rotary vacuum evaporator (40°C/20 mm Hg). The resulting brown viscous liquid was dried al 40⁰C and 0.01 mbar to constant weight. The product (yield 74 wt %) was analyzed by ¹H NMR and ¹⁹F NMR

spectroscopy. Alternative Process for Hydroiysis of Ethyienated Copolymer:

A 50 ml two-neck round-bottom flask equipped with a reflux condenser and magnetic stirrer was charged with 3,1 g (0.0021 moles) of ethyienated copolymer and 16 g (0.22 moles) of DMF. This mixture was stirred for 30 min. under nitrogen atmosphere. Then 1 g of water was added dropwise through a septum. The reaction was heated up to 100³C and kept stirring for 36 hours. After cooling to room temperature, 50 ml of butanone was added and the resulting mixture was washed with water (3 x 50 mi). The organic layer was dried over MgSO₄ and filtered through sintered glass (G4), The solvents were removed using a rotary vacuum evaporator (40°C/20 mm Hg). The resulting brown viscous liquid was dried at 4O⁰C and 0.01 rnbar to constant weight. The products (yield 54 wt %) were analyzed by ¹H NMR_: ⁱ⁹F NMR proving the presence of both dio! and diformate. Saponification of the Diformate:

A 100 mi two-neck round-bottom flask equipped with a Claisen condenser and magnetic stirrer was charged with 1.39 g of hydrolyzed di- adduct (prepared above), 0.05 g (0.29 rπrnoles) of p-tolueriesulfonic acid and 50 m! of CH₃OH. The reaction was heated until the methanol started to disfiil. Then, the reaction mixture was washed with water (2 x 50 mi), CH₂C1₂ (3x30 mi) and brine (50 ml} was added to facilitate the separation. The organic layer was dried over MgSO₄ and filtered through sintered glass (G4). The CH₂Ci₂ and traces of MeOH were removed by a rotary vacuum evaporator (40°C/20 mm Hg), The resulting brown viscous liquid was dried at 40 ⁰C and 0.01 mbar to constant weight. The product (yield 81 wt %) was analyzed by ¹H NMR and ¹⁵F NIVfR proving the presence of diol, Conversion to the Diacryiate:

A 250 ml two-neck round-bottom flask equipped with a refϊux condenser and magnetic stirrer was charged with 25.0 g (19.2 mmoies) of dio! synthesized above dissolved in 100 rnl of THF (dried), and 12 g of po!y{viny!pyridine). The reaction mixture was cooled to O⁰C under nitrogen atmosphere and 20 mg ( 0.18 mmoies) of hydroquinone were added. Acryloy! chloride was added by syringe through a septum in four subsequent doses (4 g, 4 g, 2 g, 4 g, respectively) in the interval of 6 hrs. An additional 10 g of poiy(vinylpyridme) was added to the reaction mixture. After addition of the first dose of acryloyl chloride, the reaction temperature was kept at 40⁰C over a period of 48 hrs, Pory(vinylpyridine) was removed by filtration through sintered glass G4. Then a butanone/water (1/1 ) mixture was added and subsequently washed with water. The organic layer was dried over MgSO₄ and then filtered through sintered glass (G4). The solvents and excess acryloyl chloride were removed using a rotary vacuum evaporator (40°C/20 mm Hg). The resulting brown viscous liquid was dried at 40⁰C under 0,01 mbar vacuum to constant weight. The product (yield 81%) was analyzed by ¹H and ¹⁹F NMR.

§.E§D2Ei§.i?.

fn this example, a fluoropofymer of the invention, CH₂=CHCOO- (CH2)₃-R-(CH₂)₃-OOCCH=CH₂, wherein R is poly(vinylidene fluoride-co- perfluoro(methyl vinyl ether) [I.e. PoIy(VF₂-CO-PMVE)J₁, was made by the process of the invention. The teiechelic I-(VF2~co-PMVE)-f oligomer starting material was the same as that employed in Example 1.

Conversion to the Diiodohydrin:

A 100 ml two-neck round-bottom flask equipped with a reflux condenser and a magnetic stirrer was charged with 10.5 g (6 mmoies) of I - (VF2-CO-PMVEH 2,G5g (34.4 mmoies} of ailyl alcohol and 50 ml of CH₃CN. Then the flask was heated to 80⁰C. AIBN (2,2^'-azobisisobutyronitriie) was added in 10 doses (20 mg each) with (he addition interval of 30 min. The reaction was conducted under nitrogen atmosphere at 80³C for 21 hours. After cooling to room temperature, the reaction mixture was filtered through cotton and then the solvent and excess ally! alcohol were removed on a rotary vacuum evaporator (40°C/20 mm Hg). The resulting slightly yellow viscous liquid was dried {40°C/0.01 mbar) to constant weight. The product (yield 93%) was analyzed by ¹H and ¹⁹F NMR, and FT-! R spectroscopy.

Reduction of the Diiodohydrin to the Bis(Propyi Alcohol):

A 250 mi three-neck round bottom flask equipped with a reflux condenser and a magnetic stirrer was charged with 11.5 g (8.6 mmoles) of the above-prepared diiodohydrin, 4.8g (16.5 mmoles) of BusSnH and 50 ml of CH₃CN, Then the flask was heated to 7OX, AIBIM was added in 10 doses (55 mg each) with an Interval of 60 min. between additions. The reaction was conducted under nitrogen atmosphere at 70^cC for 12 hours. After cooling to room temperature, 0.8 g of KF was added together with 50 ml of Et≤O. Then the reaction was stirred at about 25³C for 24 hours. The reaction mixture was filtered through sintered glass (G5) to remove white solid such as BuaSπK, BugSnF or BϋaSnl. The solvents were removed on a rotary vacuum evaporator (4QX/2Q mm Hg). The crude product was dissolved in 50 ml of butanone and washed with water (2 x 50 ml). The organic layer was dried over MgSθ₄ which was then filtered through sintered glass (G4). The butanone was partly removed on a rotary vacuum evaporator and residue was precipitated from pentaπe. After cooling 12 hours at 4"C₁ pentane was carefully removed from the precipitated product by decantation. The residual solvent was removed by rotary vacuum evaporation (40°C/20 mm Hg). The resulting light yellow viscous liquid was dried (40°C/0.01 mbar) to constant weight. The product (overall yield 91 %) was analyzed by ¹H and ¹⁹F NMR and FT-IR spectroscopy. The decanted pentane was also evaporated to give a low molecular weight fraction of the desired diol. Acryiation of the Dial:

A 100 mi three-neck round bottom flask equipped with a reflux condenser and a magnetic stirrer was charged with 5.03 g (3.33 mmoies) of the above-prepared bis{propyi alcohol), 25 mi of THF, 4,5g of poiy{vinylpo!ypyroiidone), 5 mg (0.045 mmoies) of hydroqυinone and cooled to 0⁰C, Then aeryloyl chloride (4.456 g, 4 ml, 50 mmoies) was added dropwise in three closes (2 nil, 1 ml & 1 mf). After the first addition of aeryloyl chloride, the reaction temperature was increased to 40ⁿC; the two subsequent additions were completed after elapsed times of 5 and 22 hours. An additional amount of poiy(viny!po!ypyro!idone) (4.5 g) was then added to the reaction mixture. The reaction was conducted under nitrogen atmosphere at 40⁰C for 48 hours. After cooling to room temperature, the reaction mixture was filtered through sintered giass (G4) to remove poiy(viny!poiypyrolidone). The filtered po!y(viny!po!ypyrolιdone) was washed with THF. The solvent was partly removed by rotary evaporation and residue was precipitated from pentane. After 12 hours at 4^* C, the pentane was carefully decanted, leaving the precipitated product. The residual solvent was removed by rotary vacuum evaporation (40°C/20 mm Hg). The resulting paie yellow viscous liquid was dried (4CTC/Q.01 mbar) to constant weight. The product (overall yieid 91 %) was analyzed by ¹H and ¹³F NMR. The decanted pentane was also evaporated and returned a low yield (7%) of a low molecular weight fraction of the desired polymer.

Claims

What is ciaimed is:

1 , A teiecheiic diacryiate copolymer of formula CH₂=CROOO-

(CH₂)n-R-(CH₂)_n-OOCCR'=CH₂, wherein R^' is H or -CH₃, n is 1-4 and R fs an oligomer having a number average molecular weight of 1000 to 25,000 daltons, said oligomer selected from the group consisting of i) an oligomer comprising copoiymerized units of vinyiideπe fluoride and perf!uoro{methyi vinyl ether), ii) an oligomer comprising copoiymerized units of viπyiidene fluoride and hexafSuoropropylene, iii) an oligomer comprising

copoiymerized units of tetrafiuoroeihySene and perfluoro(methyl vinyl ether), and iv) an oligomer comprising copoiymerized units of

tetrafluoroefhylene and a hydrocarbon olefin.

2. A teiechelic diacrylate copolymer of claim 1 wherein n is 2 or

3,

3. A teiechelic diacrylate copolymer of claim 1 wherein said oligomer has a number average molecular weight of 1200 to 12,000 daltons. 4, A teiechelic diacrylate copolymer of claim 3 wherein said oligomer has a number average molecular weight of 1500 to 5000 daltons.

«; A teiechelic diacrylate copolymer of claim 1 wherein said oligomer comprises copoiymerized units selected from the group consisting of i) vinyiideπe fluoride, tetrafiuorαethyiene and perfiuoro(methyi vinyl ether); ii) tetrafluoroethylene, perfiuoro(methyi vinyl ether) and ethylene; iii) vinyfidene fluoride, hexaflυoropropylene and

tetrafluoroethylene; and iv) tetrafluoroethylene, vinyhdeπe fluoride and propylene.

6. A process for the manufacture of a teteeheiic diacrylate copolymer, said process comprising:

A) providing a dio! of formula HO-(C^)_n-R-(CHg)_n-OH, wherein n is 1-4 and R is an oligomer having a number average molecuiar weight of

1000 to 25,000 daitons, said oligomer selected from the group consisting of i) an oligomer comprising copoiymerized units of vinylidene fluoride and perfluoro(methyi vinyl ether), ii) an oligomer comprising copoiymerized units of vinyiidene fluoride and hexafiuoropropylene, iii) an oligomer comprising copoiymerized units of tetrafluoroethylene and

perfluoro(methy! vinyl ether), and iv) an oligomer comprising

copoiymerized units of tetrafluoroethylene and a hydrocarbon olefin; and

B) reacting said diol with CH₂-CROOX, wherein X is a haϋde and R' is H or -CH₃, to form a diacrylate copolymer of formula CHg=GROQQ-- {CH₂)n-R-(CH₂)n-OOCCR¹=CH2.

7. A process for the manufacture of a teiecheiϊc diacrylate copolymer of claim 8 wherein n is 2 or 3.

8. A process for the manufacture of a teiechelic diacrylate copolymer of claim 8 wherein said oligomer has a number average molecuiar weight of 1200 to 12,000 daitons.

9. A process for the manufacture of a teSechelic diacrylate copolymer of claim 8 wherein said oligomer has a number average molecular weight of 1500 to 5000 daitons,

10. A process for the manufacture of a teiechelic diacrylate copolymer of claim B wherein said oligomer comprises coporyrnerized units selected from the group consisting of i) vinylidene fluoride, tetrafluoroethylene and perfluoro(methy! vinyl ether); ii)

tetrafϊuoroeihyiene, perf!uoro{mefhy! vinyl ether) and ethylene; iii) vinyiidene fluoride, hexafluoropropyiene and tetrafluoroethylene; and iv) tetrafluoroethylene, vinylidene fluoride and propylene.

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