Solvent effect on thermal degradation of polystyrene

The thermal degradation of polystyrene (PS) in various kinds of solvents was studied in the temperature range from 300 to 450°C. The conversion of PS to low molecular weight products was dependent on the hydrogen donating ability of the solvents used: Solvents with greater donating ability resulted in less conversion of PS. A different degradation behavior was evident when phenols or other kind of solvents were used. These reaction properties are explained with a proposed degradation mechanism that includes hydrogen transfer steps from solvents to Intermediate PS radicals and from PS to the solvent radicals.