STUDY ON THE PROPERTIES OF COAL TAR PITCH PREPARED BY AIR BLOWING

Coal tar pitch was prepared from QI free coal tar by air blowing at 220 ℃～400 ℃. The influence of the temperature, reaction time and air flow on the structure and properties of coal tar pitch was studied. The development of mesophase for the resultant pitch was monitored by hot stage polarized microscope. The results showed that the air blowing is an effective way for raising the softening point, increasing molecular weight and producing completely isotropic pitch. But mosaic textures were obtained from the oxidized pitch, and textures varied with the oxidation condition.