Pyrolysis of polyvinylsilazane precursors to silicon carbonitride

TLDR: The pyrolysis of liquid or solid polyvinylsilazanes, cross-linked according to four different routes, was studied in the 20-1400°C temperature range.

Abstract: The pyrolysis of liquid or solid polyvinylsilazanes, cross-linked according to four different routes, was studied in the 20–1400°C temperature range. The similar behaviour and the high ceramic yields (⋍85%) are related to the reactivity of the functional groups (CHCH2, SiH, NH) which lead to highly cross-linked solids before the mineralization step. The major gases evolved above 450°C are hydrogen, methane and ethylene. During the thermal treatment SiN bonds are unaffected. The silicon carbonitride samples are dense and amorphous up to 1400°C. The thermal stability of the microtexture is due to the high carbon content.