Abstract: Grafting of α-methylacrylic acid onto the surface of PP powder was performed in water toluene medium. The effect of monomer and initiator(benzoyl peroxide)concentrations, reaction time on graft degree and graft efficiency were investigated by using the orthogonal design method. The grafted PP was characterized by means of PGC and SEM. The result showed that the monomer concentration effected the graft degree and graft efficiency greatly. The highest graft degree was 35.2% and the graft efficiency was 86.4%. The grafted PP was laminated with polar materials, such as aluminium foil and nylon, and showed much stronger adhesion than unmodified PP. The grafted PP also enhanced the interfacial surface affinity between PP and CaCO₃ in PP filled composite, and the tensile strength and impact strength of the composite was improved greatly.

Key words: heterogeneous graft copolymerization, graft polypropylene, laminated composite, filled composite, interfacial surface affinity