Single‐Step Synthesis of Chemically Cross‐Linked Polysilastyrene and Its Conversion to β‐Silicon Carbide

A new method for chemically cross‐linking polysilastyrene using divinylbenzene as the cross‐linking agent is reported. The procedure involves a single‐step synthesis using the alkali‐metal sodium to promote the polymerization of dimethyldichlorsilane in the presence of the comonomers phenylmethyldichlorosilane and divinylbenzene. The cross‐linked polymer can be readily converted to β‐SiC on pyrolysis at 1500°C. The β‐SiC obtained by this procedure is nanocrystalline and has a grain‐size distribution of 8–20 nm.