The preparation of SiC ultrafine fibers containing low amount of oxygen by the electrospinning and pyrolysis of vinyl-modified polycarbosilane

The high-temperature stability of the SiC ultrafine fibers is limited by the massive amounts of oxygen introduced during the oxidative curing process. In this study, vinyl-modified polycarbosilane (Vi-PCS) was synthesized through the hydrosilylation reaction of PCS and divinyldimethylsilane at 320 °C. The electrospun ultrafine Vi-PCS fibers were cured by heating to 320 °C in an inert atmosphere, initiating a subsequent hydrosilylation reaction. Subsequent pyrolysis at 1200 °C yielded SiC ultrafine fibers with uniform diameters (1.6–2.5 μm) and low oxygen content (4.64 wt%). The fibers retained their smooth surface morphology and flexibility up to 1700 °C due to the significant reduction of the SiCxOy phase. The resulting SiC ultrafine fibrous mats are promising materials for applications in harsh environments because of their high-temperature stability and low preparation cost.