New ceramic precursors, copolymers of polycarbosilane (PCS) and dichloromethyvinylsilane (DMVS), were synthesized by hydrosilylation with platinum catalyst. The structure of PCS-DMVS copolymers were investigated by using FT-IR and NMR spectrometers. The syntheses of PCS-DMVS copolymers were confirmed by monitoring the change of the absorption bands appearing at 3050, 2100, 1600, 480 cm^-1 on the FT-IR spectra. The syntheses of copolymers were also confirmed by the presence of peaks at 3.0, 4.5, 5.9 ppm on the ¹H-NMR spectra and at 62 and 130 ppm on the ^l3C-NMR spectra, which are the characteristic peaks of vinyl group of DMVS. The initial thermal degradation temperature, weight loss and molecular weight of PCS-DMVS copolymers were analysed by thermogravimetric analysis (TGA) and gel permeation chromatography (GPC). The initial thermal degradation temperature of PCS-DMVS copolymer was 483℃. The total weight loss was PCS-DMVS copolymer 20 wt% and significantly decreased comparing with pure PCS at the same degradation condition.

백금촉매를 이용한 hydrosilylation 반응에 의해 difunctional group을 갖는 새로운 세라믹 고분자 전구체를 합성하기 위하여 polycarbosilane (PCS )-dichloromethylvinylsilane (DMVS)공중합체를 합성하였다. 합성한 공중합체의 FT-IR 스펙트럼 결과 3050, 2100, 1600, 480cm^-1부근에서 피크 변화와 ¹H-NMR 및 ¹³C-NMR 스펙트럼의 δ=3.0, 4.5, 5.9 ppm과 δ=130, 62ppm 부근에서 DMVS의 비닐기 (CH₂=CH-)에 의한 특성 피크로부터 공중합체의 합성을 확인하였다. 또한 초기 열분해 온도와 열중량 변화 및 분자량 변화를 알아보기 위한 열중량 분석과 GPC 측정결과 촉매량이 0.3 wt%일 때 열분해 초기온도가 483℃로 중량감소는 20wt%로 가장 낮았으며 순수한 PCS의 그것에 비해 중량감소율이 현저히 낮아졌다.

Keywords: polysilane; polycarbosilane; modified polycarbosilane; preceramic polymer; platinum catalyst; thermal degradation