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 arndramatic improvement of the performance of polyolefins in environmental conditions.rnSince that time a thorough understanding of the UV-degradation mechanism ofrnpolyolefins and the mechanism of action of HALS has been achieved. However, therneffect of weather variables on the physical behavior of such additives is still not fullyrnunderstood.rnThe lecture will present recent findings on the chemical and physical behavior of HALSrnanti-oxidants added to a carbon black filled PP/EPR matrix upon exposure to outdoorrnclimates and to natural and artificially accelerated weathering techniques widely used inrnthe field of material testing. The role of water in the accelerated tests will be particularlyrnfocused on as it will be shown to strongly influence the correlation with outdoorrnweathering.rnGuidance for the development of more realistic test methods to predict the lifetime ofrnHALS containing materials will be given.