HEAT-TREATED TETRAFLUOROETHYLENE COPOLYMERS Russian patent published in 2000 - IPC

FIELD: chemistry of polymers. SUBSTANCE: described are new heat-treated tetrafluoroethylene-based copolymers prepared by reacting (A) fluorodioxol of formula I wherein R_f is perfluoroalkyl having from 1 to 5 carbon atoms; X₁ and X₂ are the same of different and are -F or CF₃; Z is selected from -F, -H-, Cl in amount of 0.1-15 mole % based on total amount of monomers, (B) perfluorinated monomer selected from hexafluoropropylene and perfluoroalkyl vinyl ether of formula: CF₂=CF-OR_f wherein R_f is C₂-C₄ perfluoroalkyl or mixtures thereof in amount of 0-15 mole % based on total amount of monomers, (C) tetrafluoroethylene in remaining amount up to 100 mole %, total amount of monomers (A) and (B) being lower on equal to 20 mole %. New copolymers have improved mechanical properties at high temperatures in combination with superb optical properties. EFFECT: improved properties of the title copolymers. 9 cl, 13 ex, 4 tbl