Manufacture of silicon carbide foam from a polyurethane foam impregnated with resin containing silicon

摘要

The invention concerns a process for preparing a silicon carbide foam consisting of attacking a polyurethane foam with an alkaline solution, impregnating it, after rinsing and drying, with a suspension of silicon powder in an organic resin, heating progressively to polymerise the resin, carbonising the polyurethane foam and resin, and finally carburising the silicon contained in the resin suspension by means of the carbon originating from the carbonisation of the foam and resin. The foams obtained are characterised by a high microporosity and a mesoporosity which is variable according to the carburising temperature. The invention finds an application in the manufacture of catalyst carriers for exhaust chambers and filters for diesel engines.