Artificial Weathering Versus Natural Exposure

Computationally-accelerated prediction of polyester-melamine coatings degradation to design sustainable organically-coated steels for outdoor applications

“…, temperature fluctuations, acid rain, or biological fouling. 1,2,35,36 It is possible that T g also plays a factor in the observed differences between accelerated and natural weathering, as coatings subjected to natural exposure are likely to spend less time above their T g than those coatings subjected to accelerated weathering.…”

“…This could be attributed to several factors impacting coatings subjected to natural weathering, which are not replicated in the accelerated weathering tests, i.e., temperature uctuations, acid rain, or biological fouling. 1,2,35,36 It is possible that T g also plays a factor in the observed differences between accelerated and natural weathering, as coatings subjected to natural exposure are likely to spend less time above their T g than those coatings subjected to accelerated weathering.…”

“…While UV-A, B, and C bulbs are all available for use within accelerated weathering cabinets and focus on different ranges of the UV region, UV-A is the most commonly experienced for external coatings on the surface of the Earth. 1 The study of polymer degradation induced by UV radiation is well-documented within the literature. [3][4][5] Absorbing UV radiation brings about photo-oxidative degradation which in turn causes the breakdown of the hydrocarbon backbone of the polymer and produces free-radicals.…”

“…It is commonly accepted that 2000 hours of accelerated weathering is approximately equivalent to 2 years of Natural weathering, providing comparable results in months rather than years. 1 However, they have been shown to offer poor comparisons to natural weathering conditions, 1,2 which limits their application. Another issue with accelerated weathering is that they must run for thousands of hours before results are available, increasing the cost, and slowing down the research process.…”

“…While UV-A, B, and C bulbs are all available for use within accelerated weathering cabinets and focus on different ranges of the UV region, UV-A is the most commonly experienced for external coatings on the surface of the Earth. 1 …”