Poly (MMA-co-OVPOSS) Organic/inorganic Hybrid Nanocomposites: Preparation and Tg Enhancement Mechanism

摘要

The soluble poly (methyl methacrylate-co-octavinyl- polyhedral oligomeric silsesquioxane) (PMMA-POSS) hybrid nanocomposites with improved T<,g> and high thermal stability were synthesized by free radical polymerization and characterized by FTIR, high- resolution H NMR, <'29>Si NMR, GPC, DSC and TGA technologies. The DSC and TGA measurements indicated that the hybrid nanocomposites had higher T<,g> and better thermal properties than the pure PMMA homopolymer. The T<,g> increase mechanism was investigated using FTIR technique, displaying that the dipole-dipole interaction between PMMA and POSS also plays very important role to the T<,g> improvement besides the molecular motion hindrance from the hybrid structure. The thermal stability enhances with increase of POSS content, which is mainly attributed to the incorporation of nanoscale inorganic POSS uniformly dispersed at molecular level.