The Influence of Precursor Structure on the Development of Porosity in Polymer-Derived Sic

J. F. Nebo, C. S. Scotto, C. A. Bennett, C. J. Brinker
1996 Materials Research Society Symposium Proceedings  
Polymer-based routes to ceramic oxides take advantage of precursor chemistry and structure to produce materials with a range of pore sizes. Polymer precursor routes to nonoxide ceramics offer products with superior thermal and chemical stability in many cases. Polymethylsilane (PMS), a versatile cross linked Sic precursor, [(MeHSi),(MeSi)y], was synthesized using published procedures to yield fluid precursors with a low (20-40%) degree of cross linking. Unique, highly cross linked (60-70%),
more » ... inked (60-70%), solid polymers were produced under reaction conditions which carefully conserve the volatile monomer. These two polymers were converted to Sic to determine the relative importance of the various contributions to porosity, and to assess the role of precursor structure on porosity development in non-oxides. Initial results indicate that precursor structure has little effect on porosity. The development of the porosity appears to be dominated by high temperature thermochemistry and/or microstructural changes.
doi:10.1557/proc-431-409 fatcat:utawzstqjvfezjofkyxg6phnpm