Preirradiation Graft Polymerization of Styrene in a Poly(tetrafluoroethylene) Film Investigated by Time-Resolved Small-Angle Neutron Scattering

Abstract

Preirradiation graft polymerization of styrene in a poly(tetrafluoroethylene) (PTFE) film was examined by time-resolved small-angle neutron scattering (SANS). A crosslinked PTFE film, thickness of which is about 50 μm, was irradiated byγ-ray and immersed in a mixed solvent of styrene monomer and toluene. SANS elucidated that graft polymerization proceeds by two reaction processes (I) and (II). In process (I) at  min, graft polymerization occurs at an interface between crystalline and amorphous PTFE domains and the grafted polystyrene segregates from PTFE, forming a thin layer with a sharp interface. In process (II) at  min, grafted PS layer starts to bridge between crystalline domains. At the end of process (II), 40% of total crystalline PTFE domain is covered by the grafted PS chains.