TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: The vinyl ether monomers having sulfonyl-fluoride-containing short pendant groups is 1,1,2,2-tetrafluoro-2-((trifluorovinyl)oxy)ethanesulfonyl fluoride and 1,1,2,2,3,3,4,4-octafluoro-4-((trifluorovinyl)oxy)butane-1-sulfonyl fluoride. The vinyl ether monomer having cyano-containing pendant group is of formula: F2C=CF-O-(-CF2-CF(-CF3)-O-)n-(-CF2-)m-CN. The reaction initiator is dinitrogen difluoride, perfluorinated alkyl peroxide, and/or persulfate. The perfluorinated alkyl peroxide is perfluorinated alkyl acyl peroxide compound, perfluorinated alkoxy acyl peroxide compound, fluorinated alkyl acyl peroxide compound, and/or fluorinated alkoxy acyl peroxide compound. The persulfate is ammonium persulfate, alkali metal persulfide, and/or alkaline-earth metal persulfide. The perfluorinated alkyl peroxide is perfluorinated propionyl peroxide, 3-chlorofluorocarbon propionyl peroxide, perfluorinated methoxyacetyl peroxide, omega -H-perfluorinated butyryl peroxide, omega -SO2F-perfluorinated-2,5,8-trimethyl-3,6,9-trioxaundecyl peroxide, CF3CF2CF2CO-OO-COCF2CF2CF3, CF3CF2CF2OCFCF3CO-OO-COCFCF3OCF2CF2CF, CF3CF2CH2CO-OO-COCH2CF2CF3 and/or CF3OCF2CF2CO-OO-COCF2CF2OCF3. The persulfate is ammonium persulfate and/or potassium persulfate. Latex emulsion polymerization reaction is also included in water phase. In latex emulsion polymerization, the emulsifier is anionic emulsifier, such as sodium aliphatate, sodium lauryl sulfate, sodium alkyl sulfonate, and sodium alkylarylsulfonate, or nonionic emulsifier, such as alkylphenol polyether alcohol, such as nonylphenol polyoxyethylene ether, polyoxyethylene fatty acid, and polyoxyethylene fatty acid ether. In latex emulsion polymerization reaction, the mass concentration of emulsifier in water is 0.1-20%, the mass concentration of vinyl ether monomers having sulfonyl-fluoride-containing short pendant groups in water is 5-30%, and the mass concentration of vinyl ether monomer having cyano-containing pendant group in water is 1-12%.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The total molar fraction of tetrafluoroethylene polymerization unit is 50-85%, preferably 70-80%, total molar fraction of polymerization unit of vinyl ether monomers having sulfonyl-fluoride-containing short pendant groups is 5-49%, preferably 15-29%, and total molar fraction of polymerization unit of vinyl ether monomer having cyano-containing pendant group is 1-10%, preferably 1-5%. The molar ratio of two kinds of vinyl ether monomers having sulfonyl-fluoride-containing short pendant groups is 0.2-0.8:0.8-0.2, preferably 0.4-0.6:0.6-0.4.