PYROLYSIS OF SILICON-BACKBONE POLYMERS TO SILICON-CARBIDE

A systematic study of the role of the composition of polysilane homo‐, co‐, and terpolymers on their pyrolysis yield to silicon carbide (SiC) was performed. The ceramic yield was found to increase as the poly(dimethylsilane) structure was substituted with hexyl and, especially, phenyl groups. the best improvement in SiC yield came from the copolymerization of low levels of silane monomers containing unsaturated groups (vinyl or allyl). For a given composition, ceramic yield increased with increasing heating rate under argon. Infrared spectroscopy and thermogravimetry were used to identify the chemical changes accompanying the pyrolysis process up to 1200°C. These changes included the formation of carbosilane linkages and Si‐H groups. Copyright © 1990, Wiley Blackwell. All rights reserved