Carbonization behavior of coal-tar pitch modified with divinylbenzene and optical texture of resultant semi-cokes

In this paper, coal-tar pitch is modified with divinylbenzene (DVB) in the presence of p-toluene sulfonic (PTS) acid. Carbonization behavior of the modified coal-tar pitch and optical texture of resultant semi-cokes are studied. The carbonization behavior is studied by thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy techniques, respectively. The optical texture of resultant semi-cokes is characterized by reflected polarized light microscopy. The results show that there are marked differences in carbonization behavior of coal-tar pitch and the modified pitches. The modification of coal-tar pitch results in an increase in carbonization yield by 10-18%. The modified pitches have many methyl and methylene functional groups, which gradually disappear and aromatization degree increases with increasing heat treatment temperature. Specially, the modification contributes to a notable improvement in the optical texture of resultant semi-cokes which varies from coarse-grained mosaics to domains.