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Polymerizations of Alkenylsilanes Using Early Transition Metal Catalysts

Published online by Cambridge University Press:  28 February 2011

John Masnovi ,
Xin Y. Bu ,
Paula Conroy ,
A. Harry Andrist ,
Frances I. Hurwitz  and
Doug Miller
John Masnovi
Affiliation:
Cleveland State University, Cleveland, OH 44115
Xin Y. Bu
Affiliation:
Cleveland State University, Cleveland, OH 44115
Paula Conroy
Affiliation:
Cleveland State University, Cleveland, OH 44115
A. Harry Andrist
Affiliation:
Cleveland State University, Cleveland, OH 44115
Frances I. Hurwitz
Affiliation:
NASA Lewis Research Center, Cleveland, OH 44135
Doug Miller
Affiliation:
Cedarville College, Cedarville, OH 45314
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Abstract

Oxidative coupling of primary alkylsilanes catalyzed by Group IVB metallocene complexes leads predominantly to linear polysilanes, as first reported by Harrod. We have investigated the polymerization of ethylsilane and vinylsilane using dimethyltitanocene in order to determine the suitability of such polymers as precursors to Si-C based ceramics for application as coatings or composite matrices. A photochemical procedure for initiation of polymerization is described. Ethylsilane forms polysilanes (which contain a -Si-Si-Si-Si- backbone) by a step growth mechanism. Vinylsilane shows some Si-Si formation; however, polymerization by several different routes, including formation of polycarbosilanes (which contain a -Si-C-SI-C- backbone) by hydrosilation reactions and crosslinking via metathesis, predominate. The carbosilane polymer has high char yield (60-75%) and appears advantageous for conversion into silicon carbide, as determined by X-ray diffraction.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 180: Symposium A – Better Ceramics Through Chemistry IV , 1990 , 779
Copyright
Copyright © Materials Research Society 1990

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References

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