Photooxidative degradation of acrylic and methacrylic polymers

The photooxidative stability of poly(methyl acrylate), poly(ethyl acrylate) , poly(ethyl methacrylate) and poly(butyl methacrylate) has been investigat ed under conditions of artificial solar light irradiation. Molecular and ch emical changes induced by the light treatment were followed by size exclusi on chromatography and Fourier transform infrared spectroscopy. The acrylate units were found to be more reactive towards oxidation, in comparison with the methacrylate ones. With short alkyl side groups chain scissions prevai led over cross-linking reactions both in acrylate and methacrylate samples. The degradation of poly(butyl methacrylate) proceeds in a completely diffe rent way, with extensive cross-linking and simultaneous fragmentation react ions. In all the samples the structure formed as result of oxidation reacti ons were similar. It has also been found that the first effect of degradati on to be detected is that connected with the changes of samples molecular w eight distributions. (C) 1999 Elsevier Science Ltd. All rights reserved.