Degradation of free radicals trapped in photopolymerized methyl methacrylate

Abstract

The thermal decomposition of free radicals trapped in photopolymerized methyl methacrylate has been studied. It has been concluded from the e.s.r. spectra and from the kinetic data obtained, that only one type of radical (alkyl) is present initially, i.e., the propagating radical in the polymerization. However, on heating, an allyl radical is formed. By contrast, gamma-irradiated monomer-free poly(methyl methacrylate) contains initially an alkyl radical and an allyl radical.