An investigation of the thermal stability and char-forming tendency of cross-linked poly(methyl methacrylate)

The thermal degradation of two network copolymers of methyl methacrylate was studied as a function of the chemical nature of the cross-linking agent and the frequency of cross-links. Unlike the linear homopolymer, both the trimethylolpropane triacrlylate and trimethylolpropane trimethacrylate networks were found to char when burned. The corresponding derivative thermograms indicate that there are dramatic differences in the thermal degradation of these polymers even in the absence of oxygen. These differences are interpreted in terms of a simple model for the kinetics of depolymerization.