Microstructures and properties of ORMOSIL comprising methyl, vinyl, and γ-glycidoxypropyl-substitued silica

Three kinds of ORMOSIL were obtained by one-step hydrolysis and co-condensation of tetraethyloxysilane (TEOS), together with methyltriethoxysilane (MTES), vinyltriethoxysilane (VTES), and γ-glycidoxypropyltrimethoxysilane (GPTMS), respectively. IR spectra demonstrate the successful modification of silica network by methyl, vinyl, and γ-glycidoxypropyl groups. The samples are mainly composed of amorphous silica phase without any detectable phase separation. The introduction of unhydrolysable organic groups retards the sol–gel process of the organoalkoxysilane and act as fillers in the silica network, leading to the condensation of the resulted ORMOSIL. Refractive index, hardness, and modulus are therefore increased.