Abstract: Dry spinning performance of PCSsolution and self crosslinking process of the PCS fiber as-spun were studied by viscosity, gel content and XRD techniques. The composition, structure and mechanical properties of SiC fibers were also characterized. Results show that the optimum spinning viscosity of PCS/xylene solution is 18.0-22.0Pa·s, self crosslinking process of the PCS fiber by dry-spun begins at 250℃ during pyrolysis process, and finishes at 550℃ to form a network structure which does not melt or dissolue. The oxygen content of the final SiC fibers is decreased to about 3.6wt%. SiC fibers prepared by dry spinning have a better β-SiC microcrystalline structure and show better oxidation resistance than those prepared by the oxidation curing.

Key words: dry spinning, polycarbosilane, SiC, fiber