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.