Abstract:Three kinds of hydrophobic nano-silica particles, silica aerogel, fumed silica and precipitated silica, were added into high-temperature vulcanized silicone rubber(HTV) by blending and vulcanization. The effects of three nano-silica particles on the physical and mechanical properties of silicone rubbers were compared and analyzed. The results indicate that silicone aerogel has the most significant mechanical reinforcement effect on silicone rubbers. The prepared composite filled with aerogel and silicone rubber exhibit the extremely high tensile strength (9.52 N/mm2), great elongation (750%), high tear strength (33.98 kN/m), highly hydrophobic contact angle (124°), extremely high hardness (70 HA), low wear rate (0.04 g/cm2), very low thermal conductivity (0.11 W/(m·K)).