Functionalised fluorinated copolymers
The invention relates to a fluorinated copolymers which are particularly based on vinylidene fluoride (VDF) or trifluoroethylene (TrFE) and particularly functionalized by functional and/or functionizable vinyl ethers. The invention also relates to methods for producing said copolymers, and to the applications thereof.
1. A fluorinated copolymer of formula (I) below:
poly[A-co-X-co-(X-E-X)] (I)
in which A is a fluorinated monomer, X is chlorotrifluoroethylene (CTFE); X is capable of copolymerizing with, said monomer A and, also with a monomer E in an alternating manner, E is vinyl ether of formula CH 2 ═CH—O—R in which R is selected from the group consisting of: alkyls; glycerol, saccharide; halogenated groups; thiols, silanes, sulfonic acid, phosphonic acids, azides, alkynes, carbonates, amines, ammoniums, amidine, aldehyde, isocyanate, urea, sulfonates, phosphonates, silicones, and fluorinated or hydrocarbon-based polymers and oligomers;
wherein A is selected from the group consisting of vinylidene fluoride (VDF), trifluoroethylene (TrFE) or mixtures thereof and wherein the proportion of moieties derived from the monomer A is greater than 85 mole %.
2. The copolymer as claimed in claim 1 , wherein the monomer E is an vinyl ether of formula CH 2 ═CH—O—R in which R is selected from the group consisting of: ethyl, butyl, iso-butyl, 2-ethylhexyl, tert-butyl, 2-chloroethyl, chloro-(2,2-dimethylpropyl) and triethoxysilane.
3. The copolymer as claimed in claim 1 , wherein the monomer E is an vinyl ether of formula CH 2 ═CH—O—R in which R is chosen from the group consisting of: saccharide thiols, silanes, phosphonic acids, sulphonic acids, azides, alkynes, carbonates, amines, ammoniums, amidine, aldehyde, isocyanate, urea, sulfonates, phosphonates, silicones, and fluorinated or hydrocarbon-based polymers and oligomers.
4. The copolymer as claimed in claim 1 , comprising:
a proportion of moieties derived from monomer E of less than 5%, and greater than or equal to 0.1%;
an X:E molar ratio of greater than or equal to 2.
5. A process for producing the copolymer of formula (I) as claimed in claim 1 , comprising a step of radical copolymerization of a reaction mixture comprising the fluorinated monomer A, the monomer E and the monomer X; the X:E molar ratio being greater than or equal to 2; the molar ratio of the monomer A being greater than 0.85; wherein the monomer A is selected from the group consisting of VDF, TrFE or a mixture thereof, the monomer X is CTFE and the monomer E is an alkyl vinyl ether (VE) of formula CH 2 ═CH—O—R in which R is selected from the group consisting of: alkyls; glycerol, saccharide; halogenated groups; thiols, silanes, sulfonic acid, phosphonic acid, azides, alkynes, carbonates, amines, ammoniums, amidine, aldehyde, isocyanate, urea, sulfonates, phosphonates, silicones, and fluorinated or hydrocarbon-based polymers and oligomers.
6. The process as claimed in claim 5 , for producing a copolymer of formula (I), wherein the monomer E is a vinyl ether (VE) of formula CH 2 ═CH—O—R in which R is selected from the group consisting of: ethyl, butyl, iso-butyl, 2-ethylhexyl, tert-butyl, 2-chloroethyl, chloro-(2,2-dimethylpropyl) and triethoxysilane.
7. The process of claim 5 , wherein:
the molar proportion of VE, in the reaction mixture, is less than 5%, and greater than or equal to 0.1%;
the X:E, chlorotrifluoroethylene:vinyl ether, molar ratio is greater than or equal to 2;
the molar proportions being related to the sum of moles of VDF, of TrFE, of CTFE and of VE.
8. The process as claimed in claim 5 , wherein said copolymer is obtained by radical solution polymerization comprising a step of copolymerization of said reaction mixture in the presence of a radical initiator and of a solvent.
9. The process as claimed in claim 8 , wherein said solvent is selected from the group consisting of 1,1,1,3,3-pentafluorobutane, acetonitrile, methyl ethyl ketone, dimethyl carbonate, 2,2,2-trifluoroethanol, tert-butanol, hexafluoroisopropanol, methyl acetate, ethyl acetate, cyclohexanone and water, and mixtures thereof.
10. The process as claimed in claim 5 wherein said copolymer is obtained by radical suspension polymerization comprising a step of copolymerization of said reaction mixture in the presence of water, of an initiator, optionally of a dispersing agent, and optionally of a chain transfer agent.
11. The process as claimed in claim 5 wherein said copolymer is obtained by radical emulsion polymerization comprising a step of polymerization of said reaction mixture in the presence of water, of a surfactant and of an aqueous dispersion of initiator.
12. The process as claimed in claim 5 comprising an additional step of functionalization of said VE monomer.
13. Coatings comprising at least one copolymer as claimed in claim 1 .
14. Membranes comprising at least one copolymer as claimed in claim 1 .
15. Electroactive devices comprising at least one copolymer as claimed in claim 1 .
16. The copolymer of claim 1 , wherein the copolymer comprises a proportion of moieties derived from the monomer A of greater than 90%.
17. The copolymer of claim 1 , wherein the copolymer comprises less than 10 mole % (X-E-X) moieties.
18. The copolymer of claim 1 , wherein the chlorotrifluoroethylene:vinyl ether molar ratio X:E is equal to 2.
19. The copolymer of claim 1 , having a molar mass from 150 000 to 500 000 g/mol.