CROSS-LINKING OF HYDROPOLYSILANES FOR USE AS SILICON-CARBIDE PRECURSORS

Cross-linking reactions of hydropolysilanes with alkyl halides as cros s-linking agents were evaluated in order to obtain high yields of oxyg en-free silicon carbide ceramics. On the basis of data from infrared s pectroscopy, thermogravimetry, solubility, gel permeation chromatograp hy, and ultraviolet spectroscopy, it has been found that the cross-lin king reactions of the polymer occurred to varied extents depending on the type of alkyl halides used. The reactivities of alkyl halides to h ydropolysilanes were found to be dependent on the type of halogen, the number of halogen atoms attached to the same carbon atom, the size of the alkyl group, and the reaction temperature.