Conversion of polymers of methyl- and vinylsilane to SiC ceramics

Book · Fri Dec 30 23:00:00 EST 1994

OSTI ID:51622

Hurwitz, F I ^[1]; Kacik, T A; Bu, X Y; Masnovi, J; Heimann, P J; Beyene, K ^[2]

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1. NASA Lewis Research Center, Cleveland, OH (United States)
2. Cleveland State Univ., OH (United States)

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 {sup 29}Si NMR; methylsilane polymerizes to a polysilane, while vinylsilane polymers have a predominantly 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 1,400 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 1,400 C.

• OSTI ID: 51622
• Report Number(s): CONF-940411--; ISBN 1-55899-246-4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
EXPERIMENTAL DATA
FOURIER TRANSFORM SPECTROMETERS
INFRARED SPECTRA
NUCLEAR MAGNETIC RESONANCE
ORGANOMETALLIC COMPOUNDS
POLYMERS
PYROLYSIS
SILANES
SILICON CARBIDES
SYNTHESIS
THERMAL GRAVIMETRIC ANALYSIS
X-RAY DIFFRACTION