XU Yunshu, FU Yibei, SONG Yongcai, et al. EFFECT OF IRRADIATION ATMOSPHERE ON CHEMICAL STRUCTURE AND PYROLYSIS PROPERTIES OF POLYCARBOSILANE CERAMICS PRECURSOR FIBERS CURED BY γ-RAY[J]. Journal of Radiation Research and Radiation Processing, 1999,17(3):145-150.
XU Yunshu, FU Yibei, SONG Yongcai, et al. EFFECT OF IRRADIATION ATMOSPHERE ON CHEMICAL STRUCTURE AND PYROLYSIS PROPERTIES OF POLYCARBOSILANE CERAMICS PRECURSOR FIBERS CURED BY γ-RAY[J]. Journal of Radiation Research and Radiation Processing, 1999,17(3):145-150.DOI:
Polycarbosilane (PCS) ceramics precursor fibers were sealed in quartz tubes filled with N,2,He,NH,3, and air,irradiated to 1~15MGy by γ-ray, then converted to SiC ceramics fibers at 1200 C. Results showed that these filling gases have no significant effect on the FTIR spectra of the irradiated PCS fibers. But serious oxidation of Si-H group was observed in the samples which were irradiated in open air. By using TGA-FTIR coupled analyzing technique and gas chromatography, CH,4, and a lot of H2 were detected in the evolved pyrolysis gaseous product. When absorbed dose reached to 13.8MGy the irradiated PCS fibers become infusible fibers,and metal like black SiC fibers were obtained by heating the irradiated fibers to 1200℃ in N,2, gas. The oxygen content (1.1wt%) is much lower than conventional SiC fibers by oxidation curing method. No defects were observed in the SEM photos of these SiC fibers.