Environmental degradation of a novel ethylene–propylene copolymer in thick sheets

The outdoor ageing of a commercial ethylene–propylene copolymer (Adflex) is investigated. Different techniques (infrared spectroscopy, thermal analysis, scanning electron microscopy, mechanical tests and positron annihilation lifetime spectroscopy) are used in order to obtain a comprehensive view of the modifications occurring during the environmental ageing of thick sheets of this copolymer. The degradation of the material is ascribed to a morphology variation, arising from the separation of amorphous oxidised copolymers initially dispersed in the bulk of the material. Weathering process takes places with increase of the bulk density of the sample.