Polymer derived Si–C–B–N ceramics via hydroboration from borazine derivatives and trivinylcyclotrisilazane

2,4,6-Trimethyl-2,4,6-trivinylcyclotrisilazane (VSZ) and borazine (B3N3H6) were used as starting materials to synthesize a preceramic polymer for a Si–C–B–N ceramic. The product was obtained as a soluble gel polymer by hydroboration between vinyl and B–H groups at 0 °C to room temperature for 30 h by the standard Schenk technique. The polymer-to-ceramic conversion at a ceramic yield of 70–75% was investigated by simultaneous TG/DTA, 13C and 29Si MAS-NMR, IR, XRD, TEM and XPS. The polymer-derived SiCBN ceramic remained as an amorphous solid up to 1400 °C, and crystallized slightly at 1800 °C to show mixed XRD patterns for Si3N4, SiC and BN. The ceramic product obtained at 1000–1400 °C exhibited excellent oxidation resistance in air. In addition, it was demonstrated that dense and smooth ceramic films were readily prepared by spin-coating the liquid polymer.