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

In this study, under solvent-free condition, the vinyl-functionalized polyborosiloxane (BSiOVi) 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 BSiOVi 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 BSiOVi 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 BSiOVi showed that the BSiOVi after heat treatment possessed the higher compressive strength than that of silicone rubber. This is because that the polymerization of Si-CH=CH2 groups could improve the crosslinking density, and the ceramic transformation of BSiOVi after heat treatment tend to the formation of dense SiBOC nanocomposites. We believed that the BSiOVi could be effectively served high temperature resistant matrix resin for ceramic matrix.