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Thermochemical transformations of polycarbosilane precursors into a ceramic matrix

Research paper by N. I. Shvets, V. T. Minakov, V. S. Papkov, M. I. Buzin, L. Yu. Bad’ina, A. A. Shimkin

Indexed on: 13 Sep '14Published on: 13 Sep '14Published in: Russian Journal of Applied Chemistry



Abstract

The possibility of preparing polymeric ceramic-forming precursors from polycarbosilane and oligosilazane was examined. Oligosilazane as a component of polycarbosilane formulations acts as a curing agent, ensuring curing at 150–300°C in the absence of oxygen and modifier. Pyrolysis of the cross-linked copolymer in argon yields an inorganic matrix whose yield is 1.3 times higher than that of pyrolyzates of the starting components. The major phase of the ceramic products obtained, according to the results of X-ray diffraction and chemical analyses, is X-ray amorphous silicon carbide. The ceramic obtained is highly resistant to thermal oxidation (up to 1400°C). The composition of the ceramic and the heat resistance and service characteristics of ceramic-matrix composite materials prepared on its basis using the “polymer technology” can be controlled by varying the ratio of the initial oligomers.