Natural and artificial photo-aging of non-stabilized and pigmented, hindered-amine stabilized propylene-ethylene copolymers

This paper describes the chemical evolution of two propylene-ethylene copolymer formulations, non-stabilized and carbon black filled - HALS stabilized, exposed to a range of natural and artificially accelerated weathering techniques, commonly used in the field of material testing. With the non-stabilized formulation, a fairly good representation of weathering in outdoor conditions was demonstrated with any of the accelerated exposures through the recognition of similar chemical changes at the molecular level. In contrast, the additives in the stabilized matrix induced very different chemical evolutions depending on the weathering techniques employed. This variability has been used to critically characterize those techniques on a scientific basis.