The thermal degradation of poly(methyl methacrylate)

A survey is made of the experimental and theoretical studies of the thermal degradation of poly(methyl methacrylate). The mechanism proposed by G ORDON is shown to be incorrect. At 300°C the reaction causing complete depolymerisation of the fraction of a polymer sample which is stable at 270°C. is initiated at random in the polymer molecules. It is shown that care must be taken when interpreting percentage molecular weight versus percentage degradation plots as a guide to mechanism of a depolymerisation reaction.