Isobaric temperature dependence of radical generation in poly(methyl methacrylate)

In this study the effect of temperature on the generation of free radicals accompanying the decomposition of benzoyl peroxide in poly(methyl methacrylate) was studied. The concentration of the chain-end radicals was determined by the ESR method. The known nine-line spectrum of the chain-end radicals of poly(methyl methacrylate) was observed. This spectrum was affected by the contribution of chain radicals at higher temperatures. The dependence of the chain-end radical concentration on the annealing temperature of polymer found for different pressures gives information on the conditions under which free radicals arise and decay in the temperature range between 90 and 170°C at pressures ranging from 2000 to 12000 atm.