The oxidative degradation of heterophasic ethylene-propylene copolymers: A comparison of photoproduct formation under natural and accelerated conditions

Abstract

The natural weathering behaviour of various heterophasic ethylenepropylene (E-P) copolymers and their fractions was studied. The results are compared with those for polypropylene homopolymer (PP). The extent of natural weathering was monitored by Fourier transform infrared spectroscopy. Also, the photo-oxidation behaviour of isotactic PP, heterophasic E-P copolymers and their fractions under natural exposure were compared with corresponding photoirradiated samples. The photoproducts are produced in the same relative proportions under accelerated and natural exposure, which shows that the mechanisms by which they are formed are not related to the temperature and the photon flux.