Thermal stability and crosslinking of hydropolysilanes for use as silicon carbide precursors
Tóm tắt
Thermal stability of [(CH3SiH)30(C6H5SiCH3)70]n a hydropolysilane copolymer, in vacuum and its crosslinking reactions with vinylic silanes as crosslinking agents was evaluated in order to obtain high yields of oxygen-free silicon carbide ceramics. It was found that the polymer was thermally stable in vacuum up to 140 °C for 20 hrs based on Fourier transform infrared spectroscopy analysis. The crosslinking reactions of the polymer occurred to various extents depending on the type of vinylic silanes used as evidenced by Fourier transform infrared spectroscopy, ultraviolet spectroscopy, gel permeation chromatography, thermogravimetry and solubility data. The additions of vinylic silanes to Si-H in the hydropolysilane were found to obey anti-Farmer's rule, despite Farmer's addition of unsaturated hydrocarbons to Si-H.
Tài liệu tham khảo
S. Yajima, J. Hayashi, M. Omori and K. Okamura,Nature,261, 683 (1976). (b) S. Yajima, K. Okamura, T. Matsuzawa, Y. Hasegawa and T. Shishido,Nature,279, 706 (1979). (c) S. Yajima,Phil. Trans. R. Soc. Lond.,A294, 419 (1980). (d) S. Yajima, Y. Hasegawa, J. Hayashi and M. Iimura,J. Mater. Sci.,13, 2569 (1978). (e) S. Yajima, K. Okamura, J. Hayashi and M. Omori,J. Am. Ceram. Soc.,59, 324 (1976). (f) Y. Hasegawa, M. Iimura and S. Yajima,J. Mater. Sci.,15, 720 (1980). (g) S. Yajima, J. Hayashi and M. Omori, U.S. Pat. 4, 100, 233 (1979). (h) S. Yajima, J. Hayashi and M. Omori,Chem. Lett., 931 (1975).
R. West, L. D. David, P. I. Djurovich, H. Yu and R. Sinclair,Ceramic Bull. 62, 899 (1983).
H. Qiu and Z. Du,J. Polym. Sci., Part A,27, 2849 (1989). (b) H. Qiu and Z. Du,J. Polym. Sci. Part A,27, 2861(1989).
T. M. Hsu, Ph. D. Thesis, University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA (1991).
R. West and P. I. Djurovich, U. S. Pat. 4,602,050, July 22 (1986). (b) R. West,J. Organomet. Chem.,300, 327 (1984). (c) K. J. Wynne and R. W. Rice,Ann. Rev. Mater. Sci.,14, 297 (1984).
P. Trefonas, P. I. Djurovich, X. H. Zhang, R. West, R. D. Miller and D. Hofer,J. Polym. Sci., Polym. Let. Ed.,21, 819 (1983). (b) R. West,J. Organomet. Chem.,300, 327 (1984).
R. M. Silverstein. G. C. Bassler and T. C. Morrill,Spectrometric Identification of Organic Compounds, 4th ed. (1981).
A. L. Smith,Analysis of Silicones.Wiley Interscience, New York (1974). (b) L. J. Bellamy,The Infrared Spectra of Complex Molecules, 3rd ed., Chapman and Hall, London (1975). (c) A. L. Smith,Spectrochim. Acta.,16, 87 (1960).
Y. T. Shieh, Ph. D. Thesis, University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA (1992).
F. C. Schilling, A. J. Lovinger, J. M. Zeigler, D. D. Davis and F. A. Bovey,Macromolecules,22, 3055 (1989). (b) R. West, R. Menescal, T. Asuke and C. H. Yuan,Polym. Preprints,31, 248 (1990).
P. A. Bianconi and T. W. Weidman,J. Am. Chem. Soc., d110, 2342 (1988). (b) P. A. Bianconi, F. S. Schilling and T. W. Weidman,Macromolecules,22, 1697 (1989). (c) W.L. Wilson and T. W. Weidman,Poly. Preprints,31, 260 (1990).
A. D. Petrov, B. F. Mironov, V. A. Ponomarenko and E. A. Chernyshev,Synthesis of Organosilicon Monomers, Consultants Bureau, New York (1964).