Development of preforming pitch for carbon-carbon composites from coal-based precursors

Preforming pitch, a special type of pitch, used for the matrix formation of carbon-carbon composites, has been developed from suitable coal-based precursors, using the techniques of distillation, condensation and polymerization. The effects of various processing parameters, namely the temperature and period of heat treatment, and the atmosphere (inert or partial vacuum) during the heat treatment, on the characteristics of the resulting pitch have been studied. Some of the pitches were subjected to field trials from which the characteristics of a good preforming pitch leading to a carbon-carbon composite of density around 1.8 g cm^–3 have been identified.