Curing preceramic SiBNC polymers infusible by radical polymerization

Abstract

Borosilazane polymers carrying vinyl groups were examined as precursors for shaping and curing polymeric green bodies. The unsaturated C–C bonds present have allowed to cure these blends infusible using the radical starter dicumyl peroxide within 75 min at 130 °C, and within 5–15 min at 160 °C. A fully vinyl-functionalized single source precursor is compared with copolymers made from established borosilazanes with vinylsilazanes. The resulting ceramics are at least stable up to 1556 °C against crystallization, an initial mass loss of 2.5% is observed at temperatures of 1800 °C for some systems. Surprisingly, the ceramics with the highest temperature stability and crystallization resistance were not achieved via the homogeneous single source precursor, but from a copolymer of aminolysed trichlorosilylamino-dichloroborane (TADB) with vinyl-methyl-silazane.