Abstract
Precursor fibers for SiC based fibers were synthesized from Polycarbosilane (PCS) - Polymethylsilane (PMS) polymer blends. Addition of 0.5 mass% PMS can be melt-spun. Addition of 20 mass% PMS, however, requires an addition of a cross-linking inhibitor for melt-spinning. PMS addition is generally effective to increase resultant ceramic yields and to maintain fiber strength after high temperature exposures. In the PMS containing precursor fibers, a holding at 573K during the pyrolysis process is remarkably effective to increase the ceramic yield and the strength. PMS probably acts as a cross-linking agent at 573K to combine PCS chains.