Mechanism of radiation-induced graft polymerization into fluorinated polymer substrates studied by new characterization method of graft polymers

Hamakawa, Shotaro; Hasegawa, Shin; Maekawa, Yasunari

The graft polymers of a graft-type polymer electrolyte membrane consisting of poly(styrenesulfonic acid) (PSSA) attached on thermally stable fluorinated polymer substrates detached from the polymer substrate without decomposition or scission of graft polymer chains. In this work, the molecular weights of detached graft polymers were analyzed by gel permeation chromatography to investigate the mechanism of radiation-induced graft polymerization of styrene into the fluorinated polymer substrates. The number average molecular weight (Mn) of graft polymers seemed to be constant with Mn of about 3500 in the range of grafting degrees between 6 and 86%. Thus, graft polymerization proceeds with quite fast initiation and termination reactions to give a similar Mn of the graft polymers during the whole course of graft polymerizations.