Pyrolysis of polycarbonate in coal-tar pitch

The thermal degradation of polycarbonate in coal-tar pitch was studied. The composition of the liquid products of pyrolysis was determined with the use of gas chromatography-mass spectrometry; the modified coal-tar pitch and the pyrolysis residue were studied by Fourier transform IR spectroscopy, elemental analysis, and the determination of softening point, concentrations of substances insoluble in toluene and quinoline, and yields of volatile substances. Because of chemical interaction with coal-tar pitch, the thermal degradation of polycarbonate in coal-tar pitch occurs at considerably lower temperatures than destruction without a solvent with high selectivity for phenol and p-isopropylphenol. Hydrogen transfer from the coal-tar pitch to the polycarbonate degradation products initiates polycondensation reactions in the coal-tar pitch.