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Conversion of Polymers of Methyl- And Vinylsilane To Sic Ceramics

  • Frances I. Hurwitz (a1), Terrance A. Kacik (a2), Xin-Ya Bu (a2), John Masnovi (a2), Paula J. Heimann (a2) and Kassahun Beyene (a2)...

Abstract

Poly(methylsilane) and poly(vinylsilane) were synthesized using a titanocene catalyst, and their pyrolytic conversion to ceramics was followed using a combination of thermal analysis and infrared spectroscopy. The two polymers have distinctly different backbone structures, as determined by 29Si NMR; methylsilane polymerizes to a polysilane, while vinylsilane polymers have a predominately polycarbosilane backbone, with some polysilane structure as well. The pyrolysis path and char yield were dependent primarily on backbone structure, with little influence of polymer molecular weight. The majority of the weight loss on conversion occurs below 650 °C, although bond rearrangement continues to 1400 °C. Poly(vinylsilane) produced a C-rich Si-C ceramic in which the carbon was dispersed on a sufficiently fine level to show resistance to oxidation on heating in air to 1400 °C.

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1 Masnovi, J. et al. , “Syntheses, structures and properties of polycarbosilanes formed directly by polymerization of alkenylsilanes,” Materials Research Society Symposium (Materials Research Society, San Francisco, 1992), vol. 271, pp. 771-776.
2 Hurwitz, F. I., Heimann, R J., Gyekenyesi, J. Z., Masnovi, J., Bu, X.-Y., “Polymeric routes to silicon carbide and silicon oxycarbide CMC,” Ceram. Eng. Sei. Proc. 12, 1292-1303 (1991).
3 Masnovi, J. et al. , “Polymerization of alkenylsilanes using early transition metal catalysts,” Materials Research Society Symposium (Materials Research Society, San Francisco, 1990), vol. 180, pp. 779-784.
4 Samuel, E., Harrod, J. F., “Synthesis and characterization of a novel bis(cycIopentadienyl)titanium hydride complex,” J. Am. Chem. Soc. 106,18591860 (1984).
5 Harrod, J. F., in Inorganic and Organometallic Polymers Zeldin, M., Wynne, K. J., Allcock, H. R., Eds. (American Chemical Society, 1988), vol. 360, pp. 89100.
6 Harrod, J. F., Yun, S. S., “Silyltitanocene complexes as catalysts for the hydrogénation, isomerization and hydrosilation of olefins,” Organometallics 6,13811387 (1987).
7 Corriu, R. J. P., Leclercq, D., Mutin, P. H., Planeix, J.-M., Vioux, A., “Mechanism of pyrolysis of polycarbosilanes: poly(silylethylene) and poly(dimethylsilylethylene),” Organometallics 12,454462 (1993).
8 Lin-Vien, D., Colthup, N. B., Fateley, W. G., Graselli, J. G., The Handbook of Infrared and Raman Characteristic Frequencies of Organic Molecules. (Academic Press, Boston, 1991).
9 Walsh, R., “Bond dissociation energy values in silicon-containing compounds and some of their implications.,” Ace. Chem. Res. 14, 246252 (1981).
10 Hasegawa, Y., Okamura, K., “SiC-C composite materials synthesized by pyrolysis of polycarbosilane,” J. Mater. Sei. Lett. 4, 356358 (1985).
11 Shiina, K., Kumada, M., “Thermal rearrangement of hexamethyldisilane to rimethyl(dimethylsilylmethyl)silane.,” J. Org. Chem. 23, 139 (1958).
12 Zhang, Z.-F. et al. , “Poly(methylsilane)-a high ceramic yield precursor to silicon carbide,” J. Am. Ceram. Soc. 74, 670673 (1991).

Conversion of Polymers of Methyl- And Vinylsilane To Sic Ceramics

  • Frances I. Hurwitz (a1), Terrance A. Kacik (a2), Xin-Ya Bu (a2), John Masnovi (a2), Paula J. Heimann (a2) and Kassahun Beyene (a2)...

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