EFFECT OF GRAPHITE OR FeCl_3-GRAPHITE INTERCALATION COMPOUNDS ON THE MESOPHASE DEVELOPMENT IN COAL TAR PITCH

摘要

The influence of the addition of first stage FeCl_3-graphite intercalated compounds (GIC) or pristine graphite to coal tar pitch (CTP) upon the formation and the development of mesophase has been studied at 400, 430 and 450℃. Differences in the final samples were principally observed and studied via polarized light microscopic examinations of partially carbonized portions of the green-cokes. The insolubility was also investigated. The addition of pristine graphite to CTP inhibits the development of the mesophase: its presence generates a physical barrier which hinders the mobility and the coalescence of mesophase spherules. In the case of the addition of GIC to the CTP, the Lewis acid FeCl_3 desorbed out of the graphene layers plays the role of a catalyst during the early stages of the mixture carbonization, by enhancing the rate of formation of the mesophase.