Effects of AlClNaCl content on the formation of mesocarbon microbeads

Mesocarbon microbeads (MCMB) have been synthesized from coal tar pitch with the molten salt mixture composed of AlCl3 and NaCl at 300°C for 1h. The effects of the molten salt on the synthesis of MCMB have been studied. The results indicate that the content of molten salt has an important effect on the formation of mesophase, and the polymerization basically reaches the equilibrium when the weight ratio of molten salt mixture to coal tar pitch is 1. The molten salt can promote the formation of mesophase at low temperature, and the pyrolytic products show the optical anisotropy. Microcrystalline structure of extracted product gets more regular and the yield increases with the molten salt content increasing, but microcrystalline structure at the ratio of 1 gets disordered. When the ratio is over 2, the yield is high, and the obtained MCMB show a smooth surface, small dimension and lamellar structures whose building units are molecular layers.