Preparation and characterization of carbon foam derived from coal pitch

•The amount of light fractions in pitches affects foaming process then produces different carbon foam.•Results demonstrate foaming temperature, foaming time and foaming pressure imposing great influence on the performance of carbon foam.•The carbon foam produced by purified coal tar possesses good performance.•The carbon foam produced by purified coal tar have low thermal conductivity: there are many interspace between amorphous carbon layers decreased the speed of heat transfer.

Carbon foams with high mechanical strength and low thermal conductivity were produced using precursors obtained after thermo-oxidation treatment of purified coal-tar by self-foaming. The structure and properties of obtained foams were studied. The results indicate that foaming precursor pre-treated by varying temperature and time, and the varying foaming conditions significantly affect the foaming process, foam structure and foam mechanical properties. Foam formation can happened at relatively low pressure and fast heating rate during the foaming process because of the resultant pitches. The properties of resultant foams were studied. The influence of foaming temperature, foaming time, foaming pressure on the foaming process were discussed. And at the same time the pre-treating temperature and time of coal pitch on the foaming process were also discussed in this paper.