The effect of phenyl modified fumed silica on radiation resistance of silicone rubber

Three kinds of treated fumed silica were prepared with methylphenyldimethoxysilane (MPHTS), diphenyldiethoxysilane (DPHTS), and phenyltriethoxysilane (PHTS) as treating agents, respectively, and characterized by N2 adsorption, diffuse reflectance ultraviolet–vis spectra (DRUVS), titration and element analyzer. The results show that compared with untreated silica there are less surface hydroxyl groups retained on the treated silica, and the phenyl groups are introduced onto the silica surface. The treated silica was used as reinforcing filler for silicone rubber to investigate the resistance to irradiation of the silicone rubber obtained thereout. The mechanical properties and the average molecular weight between crosslinking points (Mc) of the silicone rubber were measured before and after irradiation. The dynamical mechanical properties of the silicone rubber were evaluated by dynamic mechanical analysis (DMA) before and after irradiation. It was found that the treated fumed silica cannot only effectively improve the radiation resistance of silicone rubber but also has excellent reinforcing effect on silicone rubber.