Perfluoroether fluororubber and preparation method therefor and use thereof

A preparation method for a perfluoroether fluororubber, wherein the perfluoroether fluororubber is prepared by a stepwise polymerization method;

• wherein, the polymerization monomers in each step of polymerization comprise tetrafluoroethylene and a perfluoroalkyl vinyl ether;
• wherein the polymerization monomers in each step of polymerization further comprise a vulcanization point monomer;
• the stepwise polymerization method is a three-step polymerization method, comprising:
• (1) subjecting pre-polymerization monomers composed of a vulcanization point monomer, tetrafluoroethylene and a perfluoroalkyl vinyl ether to a pre-polymerization reaction;
• wherein molar ratio of the vulcanization point monomer, tetrafluoroethylene and the perfluoroalkyl vinyl ether in the pre-polymerization monomers is (1-3):(60-70):(30-40);
• (2) further adding mid-polymerization monomers composed of a vulcanization point monomer, tetrafluoroethylene and a perfluoroalkyl vinyl ether for a mid-polymerization reaction;
• wherein molar ratio of the vulcanization point monomer, tetrafluoroethylene and the perfluoroalkyl vinyl ether in the mid-polymerization monomers is (0.1-1):(35-55):(40-65);
• and
• (3) further adding post-polymerization monomers composed of a vulcanization point monomer, tetrafluoroethylene and a perfluoroalkyl vinyl ether for a post-polymerization reaction, and collecting reaction product comprising perfluoroether fluororubber;
• wherein molar ratio of the vulcanization point monomer, tetrafluoroethylene and the perfluoroalkyl vinyl ether in the post-polymerization monomers is (1-3):(60-70):(30-40).