Synthesis and Characterization of Novel Preceramic Polymer for SiC

Polyphenylcarbosilane as a novel preceramic polymer for SiC was synthesized from thermal rearrangement of polymethylphenylsilane around 350 C {approx} 430 C. Characterization of synthesized polyphenylcarbosilane was performed with {sup 29}Si, {sup 13}C, {sup 1}H NMR, FT-IR, TG, XRD, and GPC analysis. From FT-IR data, the band at 1035 cm{sup -1} was very strong and assigned to CH{sub 2} bending vibration in Si-CH{sub 2}-Si group, indicating the formation of the polyphenylcarbosilane. The average of the molecular weight (M{sub w}) of the polyphenylcarbosilane synthesized was 2,500 and easily dissolves in an organic solvent. TGA data indicates that polyphenylcarbosilane is thermally stable up to 400 C. However, the rapid weight loss occurs above 400 C due to the pyrolysis of polyphenylcarbosilane, and the diffraction peak of pyrolysis residue at 1200 C corresponds to the {beta}-SiC ceramic. The ceramic yield calculated from TGA is approximately 65%