Chemically Cross-linked Polysilanes as Stable Polymer Precursors for Conversion to Silicon Carbide

Cross-linked polysilanes were prepared by the co-polymerization of Me₂SiCl₂ or PhMeSiCl₂ with varying amounts of divinylbenzene (2–15% by weight) using molten sodium as the dehalogenating agent. All the cross-linked polysilanes were stable to air and could be processed thermally for conversion to silicon carbide. Polymers containing from 5–15% of the cross-linking agent underwent a uniform shrinkage during thermal treatment (1500 °C) to afford β-SiC in good yields. The ceramic was characterized by a variety of techniques including Raman and infrared spectroscopy, powder XRD, as well as Scanning Electron Microscopy (SEM). Dedicated to Prof. C. W. Allen in recognition of his outstanding contributions to inorganic polymers. Deceased in a tragic car accident in July 2004.