Thermal Stability and Mechanical Property of Vinyl-Functionalized Polyborosiloxane and Silicone Rubber

Abstract In this study, under solvent-free condition, the vinyl-functionalized polyborosiloxane (BSiO Vi ) was synthesized by reacting triethoxyvinylsilane (VTEOS) and boric acid (BA) and the chemical structures were characterized by GPC and FT-IR. The results indicated that the BSiO Vi containg Si-O-B bonds and vinyl groups was successfully synthesized. Moreover, the thermal stability and compressive strength after heat treatment were studied. TG-DTG result indicated that the BSiO Vi with more Si-O-B high energy bonds possessed the better thermal stability than that of silicone rubber only possessing Si-O-Si bonds. The results of mechanical property of BSiO Vi showed that the BSiO Vi after heat treatment possessed the higher compressive strength than that of silicone rubber. This is because that the polymerization of Si-CH=CH 2 groups could improve the crosslinking density, and the ceramic transformation of BSiO Vi after heat treatment tend to the formation of dense SiBOC nanocomposites. We believed that the BSiO Vi could be effectively served high temperature resistant matrix resin for ceramic matrix.