Preparation and properties of carbonaceous mesophase-II highly soluble mesophase from ethylene tar modified using aluminum chloride as a catalyst

A carbonaceous anisotropic mesophase, highly soluble in THF and quinoline, was prepared from ethylene tar pitch (ETP) modified using aluminum chloride as a catalyst. A mesophase pitch prepared at 360°C under vigorous nitrogen flow and stirring from ETP modified with 10 wt% of AlCl₃ at 250°C for 7 hr exhibited solubility of 80 wt% in quinoline at 90 vol% of anisotropic content, its solubilities in THF and pyridine being as high as 52 and 62 wt%, respectively. Such a high solubility of the mesophase pitch is ascribed to the naphthenic groups of its component molecules which are produced during the modifying reaction catalyzed by AlCl₃. The moderate molecular size of modified ETP is another advantage. The anisotropic mesophase of high solubility and low melting temperature is transformable into a flow domain texture by annealing. Easy spinning into highly oriented fibers is expected.