Microcellular preceramic polysiloxane materials obtained inemulsions with high internal phase content (HIPE)

In the work, microcellular materials were obtained by cross-linking of poly(methylvinylsiloxane) (V3polymer) with 1,3,5,7-tetramethylcyclotetrasiloxane (D4H) in emulsions of high internal phase content (HIPE). Systems differing in cross-linking density and reactive group (Si-H, Si-vinyl) contents were prepared by changing V3 polymer: D4H molar ratio in the reactions. It was shown that pyrolysis of such materials conducted at the temperature of 1000 °C in the inert atmosphere (gaseous argon) results in silicon oxycarbide - carbon composites. After pyrolysis, porous microstructure of the precursor is preserved. The amount of free carbon phase in the resulting ceramic material depends on the V3 polymer cross-linking density. Precursors studied in the work give high ceramic yields, ranging from 74.1% to 79.8%.