Preparation of functionalized precursor of SiC ceramic via hydrosilylation polymerization of 1,1-diphenylethylene derivatives

Polycarbosilanes were prepared via hydrosilylation polymerization of functional 1,1-diphenylethylene (DPE) derivatives (dimethyl-[4-(1-phenylvinyl)phenyl]silane (DPE-SiH) and 1-(4-methyloxyphenyl)-1′-(4-dimethylsilanephenyl) ethylene (DPE-SiH/OMe)). Both DPE-SiH and DPE-SiH/OMe were synthesized as monomers and then utilized to prepare corresponding oligomers with Si–C bonds and phenyl rings in their backbones. The DPs were calculated to be 5.9 and 6.3, respectively, while the β-additions were 88.8 and 88.0%. The Td5 of DPE-SiH and DPE-SiH/OMe oligomers were 270 and 345 °C, respectively, and their weight residue was approximately 20% even heated at a temperature near 1200 °C in nitrogen. The compact tiny pores distributed on cross section of the resultant SiC ceramics were observed with the scanning electron microscopy. The thermal analyses verified that the oligomers of DPE-SiH and DPE-SiH/OMe possessed favorable thermal stabilities and could be taken as the proper PCSs precursor for preparation of SiC ce...