Influences of surface modification of nano-silica by silane coupling agents on the thermal and frictional properties of cyanate ester resin

The surface of nano-silicon dioxide (nano-SiO₂) particles was modified by small molecular coupling agent KH-560 and macromolecular coupling agent SEA-171, respectively, to change the surface activity and structure. The modified nano-SiO₂ was then used for reinforcing cyanate ester resin (CE). Influences of the content of nano-SiO₂ and the interfacial structure over the thermal and frictional properties of nano-SiO₂/CE composites were investigated. The mechanism of the surface modification of silicon dioxide by KH-560 and SEA-171 was discussed. The experimental results show that the addition of coupling agents increased the interfacial bonding between nano-SiO₂ particles and the CE resin so that the heat resistance and friction properties of the composites were improved. After surface treatment of nano-SiO₂ by SEA-171, the thermal decomposition temperature of the 3.0 wt% nano-SiO₂/CE composites increased nearly by 75 °C and the frictional coefficient was reduced by 25% compared with that of the pure CE, and the wear resistance increased by 77%.