Olefin hydroboration of borazine with vinylsilanes as precursors of Si–B–C–N ceramics

A processible polymeric precursor for Si–B–C–N ceramics was prepared by a hydroboration reaction between borazine and dimethyldivinylsilane using no catalyst with a synthetic yield 85%. The synthesized liquid polymer with an approximately 40% ceramic yield changed to an insoluble solid via a cross-linking reaction of the unreacted vinyl groups to the B–C alkyl bridges between the borazine ring and silane as post-heated from 200 to 600 °C. The insoluble solid was then transformed to SiCN and BN amorphous structures when pyrolyzed to 1400 °C. The synthetic and ceramic conversion chemistry was thoroughly investigated by infrared, 1H, 11B, 13C and 29Si nuclear magnetic resonance spectroscopy, X-ray diffraction and thermal gravimetric analysis.