PROPERTIES OF COAL-TAR PITCH-BASED MESOPHASE SEPARATED BY HIGH-TEMPERATURE CENTRIFUGATION

Mesophase pitches which have different mesophase contents were prepare d from a coal tar pitch and separated into mesophase and isotropic pha se by high-temperature centrifugation. Properties of mesophase during its nucleation, growth, and coalescence stages were investigated by me asuring the solubility, density, C/H atomic ratio, and thermogravimetr ic analysis. Mesophase pitch is easily separated into mesophase and is otropic phase by high-temperature centrifugation. However, when the me sophase content in pitch is above 82 vol%, the centrifugal separation becomes difficult because of a very small density difference between t he mesophase and isotropic phase. The mesophase content in pitch was i ncreased by centrifugal acceleration at constant temperature. The C/H atomic ratio of the mesophase separated under higher centrifugal accel eration was also increased. QI was the main component of smaller mesop hase spheres, and beta-resin of the isotropic matrix contributed to th e growth of spheres. The density and C/H atomic ratio of mesophase wer e nearly constant at 1.385 g/cm3 and 2.00, respectively, during heat t reatment.