Effect of graphite or FeCl3-graphite intercalation compounds on the mesophase development in coal tar pitch Original Research Article

The influence of the addition of first stage FeCl3-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 °C. 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 FeCl3 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.