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Processing of Ceramic Foams from Polymeric Precursor-Alumina Suspensions

Authors :
Mohan Edirisinghe
M. Nangrejo
Xujin Bao
Source :
Cellular Polymers. 20:17-36
Publication Year :
2001
Publisher :
SAGE Publications, 2001.

Abstract

A polysilane was used as the precursor for silicon carbide (SiC) and different amounts of it was dissolved in dichloromethane. Subsequently, between 10 to 80 %wt of alumina (Al2O3) powder was added into the solutions to make SiC-Al2O3 suspensions. Cubes of polyurethane (PU) foams with open cells in the size range 500-1200μm were soaked in these suspensions and pyrolysed in flowing nitrogen to produce SiC-Al2O3 composite foams. Some foams were heated further in nitrogen to 1300°C. The foams produced consist of an open cell structure and hole-free solid struts which were also cracks free in the polysilane-Al2O3 80:2Owt% formulation. The retention of shape during processing was excellent. Shrinkage observed after pyrolysis and further heating the foams was measured and can be controlled by varying the Al2O3 content. The foams produced have porosities in the range 87 to 95%. The maximum compressive strength of the pyrolysed foams prepared using the polysilane-Al2O3 80:20 wt% formulation was 2.3MPa.

Details

ISSN :
14782421 and 02624893
Volume :
20
Database :
OpenAIRE
Journal :
Cellular Polymers
Accession number :
edsair.doi...........e466301a1756d5c2d6d072433561dd34
Full Text :
https://doi.org/10.1177/026248930102000102