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The polycarbosilane (PCS) precursor for SiC with high molecular weight and medium molecular weight distribution was synthesized from polydimethylsilane at normal pressure. The chemical formula, the number average molecular weight, and the polydispersivity index of the synthesized PCS are SiC1.94H5.01O0.028, 1135, and 1.66, respectively, which can be attributed to the higher reaction temperature used for polymerization. The polymer to ceramic conversion of PCS was completed at 900℃ with a ceramic yield of 85%. The crystallization started at 1100℃, and at 1200℃, well resolved peaks of β-SiC were formed with small amount of α-cristobalite. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies indicated the presence of nanocrystalline β-SiC.


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Synthesis and characterization of high ceramic yield polycarbosilane precursor for SiC

Show Author's information Mangesh LODHEa( )Narendra BABUaA. SELVAMbM. BALASUBRAMANIANa
Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India
FRP Institute, Chennai 600032, India

Abstract

The polycarbosilane (PCS) precursor for SiC with high molecular weight and medium molecular weight distribution was synthesized from polydimethylsilane at normal pressure. The chemical formula, the number average molecular weight, and the polydispersivity index of the synthesized PCS are SiC1.94H5.01O0.028, 1135, and 1.66, respectively, which can be attributed to the higher reaction temperature used for polymerization. The polymer to ceramic conversion of PCS was completed at 900℃ with a ceramic yield of 85%. The crystallization started at 1100℃, and at 1200℃, well resolved peaks of β-SiC were formed with small amount of α-cristobalite. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies indicated the presence of nanocrystalline β-SiC.

Keywords:

synthesis, polycarbosilane (PCS), polymer–ceramic conversion, X-ray diffraction (XRD)
Received: 10 June 2015 Revised: 22 July 2015 Accepted: 24 July 2015 Published: 24 November 2015 Issue date: April 2015
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Publication history

Received: 10 June 2015
Revised: 22 July 2015
Accepted: 24 July 2015
Published: 24 November 2015
Issue date: April 2015

Copyright

© The author(s) 2015

Acknowledgements

We are grateful to Mr. Shrikant for his help in carrying out the experiments. We further acknowledge to Mr. Niraj for valuable technical help in manuscript preparation.

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