Crosslinkable electroactive fluorinated polymers
The invention relates to a copolymer comprising units derived from monomers of vinylidene fluoride and/or trifluoroethylene, as well as fluorinated monomers X comprising a double bond and a leaving group selected from among chlorine, bromine and iodine atoms, the leaving groups being partially replaced by azide groups in the copolymer.
1. A copolymer comprising both units obtained from vinylidene fluoride and units trifluoroethylene monomers and also from fluoro monomers X comprising a double bond and a leaving group selected from chlorine, bromine and iodine atoms, the leaving groups being partially replaced by azide groups in the copolymer.
2. The copolymer as claimed in claim 1 , wherein the fluoro monomers X are selected from chlorotrifluoroethylene and chlorofluoroethylene.
3. The copolymer as claimed in claim 1 , comprising a total amount of units obtained from fluoro monomers X of 1 to 20 mol %.
4. The copolymer as claimed in claim 1 , wherein the molar proportion of leaving groups in the copolymer that are replaced with azide groups is from 5 to 90%.
5. A composition comprising the copolymer as claimed in claim 1 , wherein the composition is a solution or dispersion of the copolymer in a liquid vehicle.
6. A process for preparing a copolymer as claimed in claim 1 , comprising:
supplying a starting copolymer comprising units obtained from vinylidene fluoride and trifluoroethylene monomers and also from said fluoro monomers X;
contacting the starting copolymer with a compound comprising an azide group.
7. The process as claimed in claim 6 , wherein the compound comprising an azide group is sodium azide.
8. The process as claimed in claim 6 , wherein the contacting is carried out in a solvent selected from the following: dimethylformamide; dimethylacetamide; dimethyl sulfoxide; ketones; furans, especially tetrahydrofuran; esters; carbonates; and phosphates.
9. A process for producing a film, comprising:
applying a copolymer as claimed in claim 1 to a substrate;
crosslinking the copolymer or the composition.
10. The process as claimed in claim 9 , wherein the crosslinking is carried out according to a predefined pattern, the process subsequently comprising the removal of portions of copolymer or composition not crosslinked, by contacting them with a solvent.
11. A film obtained by a process as claimed in claim 9 .
12. An electronic device comprising a film as claimed in claim 11 .