Benzo[a]pyrene in coal tar pitch: chemical conversion in situ by alkylation

Coal tar pitch was compounded with polyester resin or polyethylene glycols of different molecular masses. The group compositions of the pitch and the products were determined, as well as elemental analyses, free radical concentrations, infrared spectra and 13C n.m.r. spectra to elucidate structural changes and substitution of BaP. Over 90% reduction in BaP content was achieved, the mechanism probably including O-alkylation, and the products would be suitable for technical uses.