ESR study of radiation chemical cross-linking of polyvinylidene fluoride in the presence of imide additions

The mechanism of radiation-induced cross-linking of PVDF (γ-irradiation at 77 K in vacuum) in the presence of N,N'-m-phenylenedimalimide, its saturated analog - N,N'-m-phenylenedisuccinimide and N-phenylmalimide, has been studied by ESR method. The nature of radicals in PVDF, additives and compositions is analysed. Polymerization of additives in PVDF matrix initiated by radicals formed under irradiation proceeds up to 100% conversion comparatively with 1-2% yield for polymerization of these monomers in their own crystalline matrix. The experimental data point out the localization of imide additives in amorphous regions of PVDF matrix. The three-dimensional network being a result of polymerization of N,N'-m-phenylenedimalimide forms with cross-linked polymer matrix the sytem of interpenetrating networks