Oxidation properties of mesophase pitch prepared by a heterogeneous nucleation method

Mesophase pitches prepared by a heterogeneous nucleation method from various mixtures of coal tar-derived isotropic pitch and petroleum-derived mesophase pitch (MP-P) were oxidatively stabilized, and the dependence of chemical reactivity and stabilization rate on their chemical structure was investigated. The rate and amount of oxygen uptake of the mesophase pitch fibres, revealed by thermogravimetry, increased under given conditions of oxidation with the amount of added MP-P, but the rate of stabilization showed a reverse trend. The lower chemical reactivity of coal tar-derived mesophase pitch (MP-C) appears to induce a slower rate of oxygen uptake, while the higher content of pyridine-insoluble fraction and higher aromaticity of MP-C may result in a lesser content of oxygen being required for stabilization, as compared with MP-P.