Methods of treating a carbon foam precursor to facilitate subsequent
foaming of the material at low pressures, which may be on the order of
about 0.5 to 1.5 atmospheres, are disclosed. In one embodiment, the carbon
foam precursor is subjected to partial devolatilization under controlled
conditions with subsequent foaming being effected at low pressure. The
carbon foam precursor may be one of various forms of coal including raw
coal, coal extract mesophase pitch, synthetic mesophase pitch or petroleum
based pitch. The prefoaming treatment of the carbon foam precursor may
remove a portion of the internal blowing agent and may alter the fluidity
of the carbon foam precursor matrix. In another embodiment, the precursor
after being converted into a powder is subjected to oxidation prior to
foaming.
