METHOD OF PRODUCING PERFLUORINATED COPOLYMERS WITH SULFONYLFLUORIDE FUNCTIONS Russian patent published in 2004 - IPC

FIELD: polymer production. SUBSTANCE: invention relates to production of perfluorinated copolymers with sulfonylfluoride functions via copolymerization of tetrafluoroethylene with perfluorocarbon vinyl ether of formula CF₂=CF-O-CF₂-CF(CF₃)-O-CF₂-CF₂-SO₂F, in fluorine-containing organic solvent or in bulk influenced by radical-type perfluorinated peroxide at elevated pressure, wherein reaction mixture is continuously fed by additional tetrafluoroethylene. Before copolymerization is started, preliminarily prepared hydrolyzed tetrafluoroethylene polymer with 9.5-15 mol % of above-indicated perfluorocarbon vinyl ether is added to reaction mixture in amount 0.3-0.66% on the weight of liquid reaction mixture in the form of dispersion in fluorine-containing organic solvent. Above-mentioned peroxide is selected from bis-perfluoro(2-oxa-p-methyl-dioxane-propionyl)peroxide, bis-perfluoro(2,5,8-trimethyl-3,6,9-trioxa-dodecanoyl)peroxide, bis-perfluoro(cyclohexanoyl)peroxide, and mixtures thereof. Process is carried out at 20-35(r) and pressure 0.25-0.6 MPa to yield copolymer containing 3.5 to 19 mol % of above-indicted perfluorocarbon vinyl ether. EFFECT: improved heat resistance and ability to be extruded into products less than 100 mcm in thickness and to form, after hydrolysis, concentrated solutions suitable for manufacturing thin films, by flooding technique, and hollow fibers with wall thickness 30-80 mcm. 7 cl, 2 tbl, 26 ex