New ceramic precursors, polycarbosilane-co-dichloromethylvinylsilane were synthesized by hydrosilylation and reduction with LiAlH₄. The structure and thermal degradation properities of new PCS-DMVS copolymers were characterized by using FT-IR, ¹H, ²⁹Si-NMR spectrometers and thermogravimetric analysis (TGA). The conversion of new PCS-DMVS ceramic precursors were about 90 percent. After thermal degradation in nitrogen gas at 1500 ℃, the ceramic yield of modified PCS-co-DMVS ceramic precursor was 93 wt% and increased 8 percent comparing with pure PCS-DMVS copolymers. The crystalline peaks were observed at 2θ=35°, 60°, 72° after heat-treatment at 1500 ℃. The crystal system of β-SiC was proved to be a cubic.

Hydrosilylation 반응에 의해 합성한 polycarbosilane-co-dichloromethylvinylsilane(PCS-DMVS)을 LiAlH₄로 환원시켜 새로운 세라믹 전구체를 합성하였다. 그들의 구조 및 열분해 특성을 FT-IR, ¹H-NMR, ²⁹Si-NMR 및 TGA를 사용하여 분석하였다. Modified PCS-DMVS 세라믹 전구체의 전환율은 약 90%이었으며 열분해 수율은 최대 93wt%로 환원전의 PCS-DMVS 보다 8% 증가하였다. 또한 열분해한 시료의 X-선 회절 실험결과 2θ=35°,60°,72°에서 결정성 피크가 관찰되었으며 이로부터 β-SiC의 결정구조가 입방체임을 확인하였다.

Keywords: polycarbosilane; modified polycarbosilane-co-dichloromethylvinylsilane; preceramic