UV DEGRADATION OF CORROSION PROTECTIVE PAINTS AND POLYMERS -GENERAL IMPLICATIONS OF CLIMATE CHANGE

摘要

Paints and polymer type coatings protect steel and other substrates from corrosion and are an important method of protection. The durability models or 'predictions on the rate of degradation to first maintenance' may be considered outdated as a result of the measured UV increase in Australia and New Zealand over the past 20 years. The further projected increase in UV exposures and the thermal conditions experience in Northern Australia (Brisbane and above) must have some impact on the validity of current durability predictions and models as used in the selection of materials in the building industry, (I.e. paints; powder coatings, polymer based coating systems; plastics, sealants, adhesives) and other polymeric materials. Durability of these materials is a function of exposure to environmental conditions (UV, thermal stress, and moisture), material type, surface finish, colour, coatings, and the albedo of the surrounding environment. These results also indicate that chemistry of polymer type materials developed in New Zealand, Europe, and North America, which incorporate UV stabilizers will most likely under-perform as UV radiation is more than 200% higher in Northern Australia than in most of Europe. This work also suggests that Australian UV Index (Lemus-Deschamps et al., 2004) could provide a valuable guide to environmental conditions and the expected durability of polymers or materials affected by UV may be incorporated in labelling or international standards and subsequent marketing to the benefit of consumers.