Hong Sik Park

Preparation of Polycarbosilane Using a Catalytic Process and Its Practical Uses

Polycarbosilane is the most typical polymeric precursor for SiC ceramic. In this study, liquid type polycarbosilane was synthesized from polydimethylsilane in the presence of solid acid catalyst at 350oC. The molecular weights of the polycarbosilane were ranged between 350 and 530. Synthesized polycarbosilane was characterized with 29Si Solid NMR, FT-IR and GPC analysis. The synthesized polycarbosilane can be used as a good organometallic precursor for SiC coating via chemical vapor deposition or spin coating.

Fabrication of Silicon Carbide Fiber and Non-Woven Fabric from the Polycarbosilane Produced Using a Catalytic Process

Continuous polycarbosilane fiber of 15~25μm and non-woven felts were prepared through melt spinning and melt blowing process using PCS having a different molecular weight. The molded fiber and felt were cured either thermally or by UV-irradiation process and pyrolyzed under an inert atmosphere to convert it into an inorganic state. The conversion process of polycarbosilane fiber and felt into SiC were characterized by FT-IR, XRD, SEM and TEM. Broad diffraction peaks in XRD around 35 o , 60 o , and 73 o appeared to correspond beta-SiC phase and high resolution image of TEM showed the nano-crystallites among the amorphous phase. The resulted SiC fiber and felt are expected to be used in a various field of high temperature applications.