분자량이 조절된 폴리카보실란으로부터 제조한 SiC Fiber의 특성분석 = Characterization of Sic fiber Derived from Polycarbisilanes with Controlled Molecular Weight

다국어 초록 (Multilingual Abstract)

Polycarbosilane was synthesized by the Kumada rearrangement of polydimethylsilane in the presence of zeolite (ZSM-5) as a catalyst at 350℃. The prepared polycarbosilane had very low molecular weight distribution (Mw=500), so that it was not suitable to fabricate SiC fiber by melt spinning. Further polymerization of PCS was conducted around 400℃ to obtain spinnable polycarbosilane. After polymerization, the polycarbosilanes were isolated by distillation according to the molecular weight distributions. The PCS with a controlled molecular weight distribution was spun into continuous polycarbosilane green fibers. The PCS green fiber was successfully transformed into silicon oxycarbide fiber. The room temperature strength of the SiC fiber was around 1.5-1.8 GPa. The oxidation behavior and the tensile strength after oxidation were also evaluated.

국문 초록 (Abstract)

SiC 섬유를 제조하기 위하여 제올라이트를 촉매로 사용하여 350℃에서 6시간 반응시켜 폴리카보실란을 제조하였다. 제조된 폴리카보실란은 80%이상의 높은 수율을 보였으나 분자량 500이하의 올리고머로서 SiC 섬유를 제조하기에 적합한 방사성을 갖지는 못했다. 따라서, 400℃의 온도범위에서 재중합을 실시하여 분자량 분포를 스피닝에 적합하도록 조절하였다. 중합된 폴리카보실란을 분별증류하여 분자량별로 분류한 후 분자량에 따른 스피닝특성 및 SiC 섬유화 특성에 대하여 분석하였다. 제조된 SiC 섬유의 상온 인장강도는 1.5-1.8 GPa 이었으며 1200oC 산화시험 후에는 섬유의 표면에 약 350 nm 의 산화층이 생성되었으나 상온강도의 저하는 없었다.

참고문헌 (Reference)

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