Composition and Structural Characterization of the Extractive Pitches as Compared with the Commercial Reference Pitches of Different Origins

Abstract

The chemical and group composition, the empirical properties and the molecular structural characteristics of the extractive pitches produced by thermal dissolution of three medium-ranked coals were studied in comparison with the reference commercial pitches including typical coal-tar pitch, petroleum-derived pitch and the pitch sample derived from the blended mixture of coal tar with petroleum feedstock. The structural parameters of the average pitch molecules have been compared based on the 1H and 13C NMR spectra. It was shown that, in terms of chemical composition and empirical properties including carcinogen content, the extractive pitches resemble blended pitch sample, the structural parameters being close to commercial coal-tar pitch sample. The average pitch molecule of extractive pitches was composed of predominantly aromatic nuclei with rather pericondensed structure.