Abstract: Plasma-induced graft copolymers of methyl methacrylate onto polypropylene (PP-g-PMMAI were used as compatilizers in the blend system of PP and polyvinylidene fluoride (PVDF).SEM and FTIR showed that it was the dipole-dipole interaction between the fluorine of PVDF and the carbonyl of PMMA of the compatilizer that made the polymers compatible. Mechanical property studies of the blend system showed that PP-g-PMMA copolymers with grafting yields of 7.7%～300% from various plasma treatment time or of 30%～80% from different post-polymerization time had the best compatibility effect.

Key words: polypropylene, polyvinylidene fluoride, blending compatibility, dipole-dipole interaction