The thermal degradation of glycidyl methacrylate-methyl methacrylate copolymers

Copolymers of glycidyl methacrylate and methyl methacrylate with widely differing compositions have been studied by thermal volatilisation analysis (TVA), thermogravimetry (TG), differential thermal analysis (DTA) and pyrolysis-mass spectrometry (Py-MS) techniques. The apparent activation energies for the decomposition of the copolymers were calculated from the results of thermo-gravimetric experiments. The condensable volatile degradation products have been identified after separation by subambient TVA (SATVA). The cold ring fraction (CRF) and the structural changes in the residue in the course of degradation were examined. Non-condensable products formed during TVA degradation were identified using a mass spectrometer attached to the TVA apparatus. The two monomers are the major products of degradation of the copolymers, which, unlike the PMMA, also yield CRF products. Anhydride rings are detected in the CRF and in the residue from partial degradation to 340 °C. Glycidyl methyl ether is also one of the degradation products. A mechanism of degradation is proposed.