FIELD: chemistry of polymers, more particularly coating of electric cables by extrusion from melts. SUBSTANCE: tetrafluoroethylene copolymer comprises links of (a) perfluoromethyl ether, (b) fluorine-containing monomer of formula: T-Rf-O-CF2-CF2 wherein P is C2-C12 perfluoroalkylene radical; T is fluorine, chlorine, hydrogen and (c) tetrafluoroethylene at definite weight ratio of links. EFFECT: copolymers have good thermal and mechanical properties at high temperatures and higher strain resistance. 5 cl, 7 ex, 2 tbl
