Abstract
Polycarbosilane (PCS) was modified by addition of 1 wt% polyborazine and subsequent heat treatment at 70-400 °C. The modified PCS exhibited highly improved ceramic yield from original 63% to 78% by heating at 70 °C for 10 h. The molecular weight of the PCS modified at higher temperatures markedly increased, then was rendered infusible but soluble PCS in organic solvent on heating at 300 °C. H-NMR indicated that original PCS was enhanced by dehydrocoupling reaction between Si-H groups. Solution of the modified PCS was hand-drawn to fibers, followed by direct pyrolysis up to 1,400 °C without air-curing step to convert into oxygen-free SiC fibers. The morphology and crystalline phase were determined by SEM and XRD analysis, respectively.
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Mr. Cao worked at CNU under co-advisor system.
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Cao, F., Kim, Dp., Ryu, Jh. et al. Modification of polycarbosilane as a precursor with high ceramic yield for oxygen-free SiC fibers. Korean J. Chem. Eng. 18, 761–764 (2001). https://doi.org/10.1007/BF02706397
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DOI: https://doi.org/10.1007/BF02706397