Patent ID: 8552623

Claim:
A polymer material comprising a poly vinylidene fluoride (PVDF)-based terpolymer that is cross-linked by cross-linking agent, wherein the PVDF-based terpolymer comprises: as a first structural unit, a vinylidene fluoride monomer; as a second structural unit, trifluoroethylene or tetrafluoroethylene; and as a third structural unit, vinyl fluoride, perfluoro (methyl vinyl ether), bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoroethylene, or hexafluoropropylene, and wherein the cross-linking agent comprises at least one selected from the group consisting of methylenediamine, ethylenediamine, N-isopropyl ethylenediamine, 1,3-phenylenediamine, 1,5-naphthalenediamine, and 2,4,4-trimethyl-1,6-hexanediamine.