Preparation and Characterization of Poly(methyl methacrylate)/Nano-silica Composite Particles

The nano-sized silica particles were modified with 3-(trimethoxysilyl) propyl methacrylate (MPS) and well dispersed in methyl methacrylate (MMA),from which poly(methyl methacrylate)/ nano-silica composite particles were prepared via in situ suspension polymerization.The nanocomposite particles were characterized using Fourier transformed infrared spectroscopy,transmission electron mi- croscopy,differential scanning calorimetry,and thermal gravimetric analysis.The nano-silica particles were well dispersed in polymer matrix and poly(methyl methacrylate) molecules were effectively grafted onto silica surface via the copolymerization between MMA and grafted MPS.When SiO_2 content and NIPS amount was 6.6 % and 0.06 g/g SiO_2,respectively,the grafted fraction of PMMA reached 78.3 %.The introduction of nano-silica into PMMA improved the heat-resistance of PMMA.When SiO_2 content was 14.7 %,the glass temperature and the temperature of maximum degradation rate were increased by 11.8℃and 18.8℃,respectively.