Effects of AlCl3 on preparation of mesocarbon microbeads

The preparation of mesocarbon microbeads (MCMB) had been carried out by heat-treating a medium coal tar pitch at 420degC for 2 hours in the presence of aluminum chloride(AlCl₃). A larger number of MCMB with small diameter were obtained. The isolated MCMB were observed by scanning electron microscope. The average diameters of the MCMB were measured by laser particle size analyzer. The Pl(pyridine insoluble) yields were determined from the weight of the extracted residue. The effects of AlCl₃ on preparation of MCMB had been studied. It was found that AlCl₃ promotes the formation of MCMB in coal tar pitch. The sphere size and PI yield increase with increasing in the amount of AlCl₃, the size distribution becomes wide gradually at the same time. The amount of AlCl₃ from 3 to 5 wt% appears opfimurn to give small MCMB, diameter below 8 mum, with good spherical shape and smooth surface at PI yield over 40 wt%.