Performance improvement of nano-silica/polypropylene composites through in-situ cross-linking approach

To prepare polypropylene (PP) based nanocomposites with improved mechanical performance, an in-situ cross-linking route was adopted by adding reactive monomers and cross-linking agents into the system containing nano-silica during melt compounding. In the meantime, the reactive monomers were polymerized and grafted onto to the nanoparticles, and the grafted polymer chains were cross-linked forming a network of the tiny reinforcement dispersed in linear PP matrix. Since the nanoparticles were interconnected by the semi-interpenetrating polymer network (semi-IPN)-like structure, the filler/matrix interaction was substantially enhanced, and both strength and toughness of the PP nanocomposites were significantly increased. (C) 2007 Elsevier Ltd. All rights reserved.