Effects of pre-oxidation and the temperature of heat treatment on composition and microstructure of MCMB

Mesocarbon microbeads (MCMB) were prepared from coal tar pitch by heat condensation in the retort, and then MCMB were stabilized at the temperature of 300°C. Composition and microstructure of MCMB after heat treatment at different temperatures were studied by element analyzer, FT-IR, XRD and HRTEM. Results indicate that oxygen content and functional groups of MCMB increased, while micro-crystal structure became worse after pre-oxidation. With the temperature of heat treatment increasing, hetero atoms emitted, functional groups decreased, La and Lc of micro-crystal increased and microstructure became regular gradually. When the temperature rose to 2300°C, the degree of graphitization of MCMB was about 89.53% and hetero atoms emitted almost all. Accordingly, the spacing of layers of MCMB was 0.3363 nm which was close to the spacing of layers of graphite, and the graphitization fringe were showed obviously in the HRTEM photographs.