CARBONIZATION AND GRAPHITIZATION BEHAVIOR OF IODINE-TREATED COAL-TAR PITCH

The authors investigated carbonization and graphitization behavior of coal tar pitch (CTP) treated with iodine. The behavior of weight decre ase and the microstructural development with increase of heat treatmen t temperature were different between non-treated and iodine-treated CT P. The carbon yield of CTP increased from 40 to 70% by the iodine trea tment. Flow type texture was obtained from non-treated specimen and is otropic texture was obtained from the iodine-treated one. Gas mass spe ctrometric analysis showed that dehydrogenative reactions were acceler ated by iodine at the temperature range from 200 to 450 degrees C. The iodine treatment was mainly effective for the benzene soluble fractio n of the CTP. The X-ray diffraction on graphitized specimens showed th at the graphitizability was able to be delayed by the iodine treatment . (C) 1997 Elsevier Science Ltd. All rights reserved.