Carbonization and graphitization behavior of iodine-treated coal tar pitch Original Research Article

The authors investigated carbonization and graphitization behavior of coal tar pitch (CTP) treated with iodine. The behavior of weight decrease and the microstructural development with increase of heat treatment temperature were different between non-treated and iodine-treated CTP. The carbon yield of CTP increased from 40 to 70% by the iodine treatment. Flow type texture was obtained from non-treated specimen and isotropic texture was obtained from the iodine-treated one. Gas mass spectrometric analysis showed that dehydrogenative reactions were accelerated by iodine at the temperature range from 200 to 450 °C. The iodine treatment was mainly effective for the benzene soluble fraction of the CTP. The X-ray diffraction on graphitized specimens showed that the graphitizability was able to be delayed by the iodine treatment.