In situ compatibilization between polystyrene‐grafted nano‐sized TiO 2 and polypropylene with Friedel‐Crafts catalyst

The application of Friedel‐Crafts (FC) alkylation reaction to the in situ compatibilization between polystyrene‐grafted nano‐sized TiO 2 (PS‐grafted TiO 2 ) and polypropylene (PP) was assessed. The PS‐grafted TiO 2 was first prepared via dispersion polymerization of styrene (St) using 3‐(trimethoxysilyl) propyl methacrylate treated nano‐sized TiO 2 (MPS‐treated TiO 2 ) as cores, and then dispersed within PP by melt blending with different contents of FC catalyst, AlCl 3 /St, to give PP/PS‐grafted TiO 2 nanocomposites. The dispersion of PS‐grafted TiO 2 in PP and interfacial adhesion of PP/PS‐grafted TiO 2 nanocomposites were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. The results indicated that the dispersion of PS‐grafted TiO 2 in PP could be improved, with an enhancement of interfacial adhesion between TiO 2 and PP, by introducing FC catalyst with adequate concentration, which led to a better thermal stability and resistance to ultraviolet (UV) aging of PP/PS‐grafted TiO 2 nanocomposites. The effect of FC catalyst on the compatibilization between the PS‐grafted TiO 2 and PP was discussed based on FC alkylation reaction mechanism. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009