Mechanical and Thermal Properties of the Hybrid Composites of Vinylester Resin and Methacryl-Substituted Polysilsesquioxane

Vinylester resin (VER) composed of bisphenol-A-based epoxy methacrylate and styrene was cured finally at 120 degrees C with methacryl-substituted polysilsesquioxane (ME-PSQ) prepared from 3-(trimethoxysilyl)propyl methacrylate and tetramethylammonium hydroxide. The dynamic mechanical and thermal properties of the VER/ME-PSQ 90/10-60/40 hybrid composites were investigated when compared with crosslinked-VER (C-VER) and VER/phenyl-substituted polysilsesquioxane (Ph-PSQ) 80/20 composite cured at the same condition. As a result, the VER/ME-PSQ hybrid composites showed much higher storage modulus (E') at rubbery state than C-VER and the VER/Ph-PSQ composite. The E' of the hybrid composites increased with increasing ME-PSO content. Also, coefficient of thermal expansion of the hybrid composites decreased with increasing ME-PSO content. The glass transition temperatures and 5% weight loss temperatures of the VER/ME-PSQ hybrid composites were almost the same as those of C-VER and the VER/Ph-PSQ composite. POLYM. COMPOS., 30:591-598, 2009. (C) 2008 Society of Plastics Engineers