Effects of surface modification of talc on mechanical properties of polypropylene/talc composites

Low compatibility of polymer matrix and dispersed filler negatively affects the performance of polymeric composites. In order to improve the adhesion between the components in a compound the polymer matrix or/and the filler particles should be modified with a compatibilizer or/and a coupling agent. An overview of our current research on the effect of the addition of silane treated and untreated talc powders on the mechanical properties of polypropylene/talc composites is presented in this paper. Different silane coupling agents (3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane) were used to improve the adhesion at the surface of talc powders. Maleic anhydride grafted polypropylene was utilized to increase the adhesion between the polypropylene matrix and talc powders. The content of maleic anhydride grafted polypropylene (MA-g-PP) was varied between 1 and 5 wt% in polypropylene/talc composites. The surface modification of talc powders has a significant effect on the interfacial structure and the mechanical properties such as tensile strength and impact strength of polypropylene/talc composites. The experiments show that polypropylene grafted with maleic anhydride together with silane surface treatment exhibits the highest potential for improvements in this field.