Effect of solvent on thermal degradation of poly( p-methylstyrene)

The thermal degradation of poly( p-methylstyrene) (P-pMS) was studied in several solvents, such as 1-methylnaphthalene, tetralin and phenol, in the temperature range 300–400°C. No undesirable by-products, such as gels and cross-linked high molecular weight products, were formed, in contrast to the significant yield of these products with conventional polymer pyrolyses without solvents. The conversion of P-pMS to low molecular weight products, and the molecular weight of the residual polymer after pyrolysis, depended markedly on the kind of solvent used. Such degradation behaviour is explained well by a proposed mechanism including hydrogen transfer from solvents to intermediate polymer radicals.