Fine SiC fiber synthesized from organosilicon polymers: relationship between spinning temperature and melt viscosity of precursor polymers

A very fine silicon carbide (SiC) fiber with diameter of 6 mum, about a hal f of that of a commercially available SiC fiber, was synthesized from a pol ymer blend of polycarbosilane (PCS) and polyvinylsilane (PVS). The fine SiC fiber was obtained by optimizing the composition and the spinning temperat ure of PCS-PVS polymer blends. In order to determine these optimum conditio ns, the relationship between temperature and melt viscosities of the polyme r blends was investigated. As a result, it was found that the optimum spinn ing temperature range was within a temperature range where the melt viscosi ty is 5-10 Pa . s. Moreover, by blending PVS with PCS, the spinning tempera ture of the polymer blends was lowered, the spinnability of polymer system was improved, and finer polymer fiber was obtained compared with PCS. The o ptimum content of PVS in the polymer blend was 15-20 wt%. (C) 2001 Kluwer A cademic Publishers.