THE IFLUENCES OF REACTION CONDITIONS ON THE PROPERTIES OF BORON-SUBSTITUTED POLYAROMATIC MESOPHASE

S: Boron substituted polyaromatic mesophase was prepared by co pyrolysis of a coal tar pitch with pyridine borane complex under autogeneous pressure. The effect of reaction conditions on the properties and microstructure of mesophase pitch was investigated. It was found that with the increase of boron addition, the yield of mesophase pitches decreased, the soften points, coke yields and insolubles in tetrahydrofurane of mesophase pitches increased gradually under the same reaction condition. About 80 %~90 % of boron was retained in the pyrolysis products. For the same boron addition, the similar results were found with the increase of reaction temperature and the elongation of reaction time.