High-temperature pyrolysis of ceramic fibers derived from polycarbosilane-polymethylhydrosiloxane polymer blends with porous structures

Kita, Kenichiro; Narisawa, Masaki*; Nakahira, Atsushi*; Mabuchi, Hiroshi*; Ito, Masayoshi*; Sugimoto, Masaki; Yoshikawa, Masahito

The polymer blends of polycarbosilane (PCS) and polymethylohydrosiloxane with high molecular weight (PMHS-h) were prepared by freeze-drying process. Melt viscosity, themogravimetric analysis, and gas evolution from the polymer blends were analyzed. The polymer blend of HSah15 (15 mass% PMHS-h to PCS) was melt-spun to fiber form, curing by thermal oxidation and pyrolyzed at various temperatures up to 1773 K. The fibers were investigated by tensile tests, FE-SEM observation, and XRD (X-ray diffraction) analysis. After pyrolysis at 1273 K, there were amounts of pores in the cross sections of the fiber derived from HSah15, and after pyrolysis at 1773 K, no remarkable -SiC crystal were formed on the outside surface of the fiber derived from HSah15.