Synthesis of core-shell PMMA-SiO2 nanoparticles with suspension-dispersion-polymerization in an aqueous system and its effect on mechanical properties of PVC composites

Well-dispersed core-shell poly(methyl methacrylate) (PMMA)-SiO2 nanoparticles were prepared in an aqueous solution by suspension-dispersion-polymerization (SDP). The particle size distribution, grafting efficiency and particle morphology were systematically investigated. It was found that the PMMA was grafted uniformly on the surface Of SiO2. The mechanism to form the core-shell nanoparticles was discussed. The core-shell nanoparticles were subsequently used as filler in a poly (vinyl chloride) (PVC) matrix, and mechanical properties of the PMMA-SiO2/PVC composites were studied. Morphological structure of PVC composites revealed that PMMA covering on SiO2 improved the dispersion Of SiO2 in the PVC matrix and enhanced the interfacial adhesion between the SiO2 and PVC. The results demonstrated that these core-shell PMMA-SiO2 nanosphere fillers could improve mechanical properties of the PVC matrix. (C) 2008 Elsevier Ltd. All rights reserved.