NATURAL AND ARTIFICIAL PHOTO-AGING OF A PIGMENTED, HALS-STABILIZED PROPYLENE-ETHYLENE COPOLYMER

摘要

The development of hindered amine light stabilizers (HALS) in the seventies led to a dramatic improvement of the performance of polyolefins in environmental conditions. Since that time a thorough understanding of the UV-degradation mechanism of polyolefins and the mechanism of action of HALS has been achieved. However, the effect of weather variables on the physical behavior of such additives is still not fully understood.This lecture will present recent findings on the chemical and physical behavior of HALS anti-oxidants added to a carbon black filled PP/EPR matrix upon exposure to outdoor climates and to natural and artificially accelerated weathering techniques widely used in the field of material testing. The role of water in the accelerated tests will be particularly focused on as it will be shown to strongly influence the correlation with outdoor weathering.Guidance for the development of more realistic test methods to predict the lifetime of HALS containing materials will be given.