Process for preparing a propylene-tetrafluoroethylene copolymer

摘要

Propylene and tetrafluoroethylene are copolymerized at the low temperature of 0 DEG -50 DEG C. in an aqueous medium in the presence of a specific redox catalyst system. The specific redox catalyst system comprises (1) a water soluble inorganic persulfate, (2) a water soluble thiosulfate or bisulfite and (3) a water soluble iron salt, and preferably further comprises a reducing sugar and a water soluble pyrophosphate. The propylene-tetrafluoroethylene copolymer having high molecular weight and low Mooney viscosity can be prepared at high copolymerization reaction rates.