Simulations of nanoscale and macroscopic property changes on coatings with weathering

Coatings are designed for and applied on a surface for both aesthetics and protection of the substrate. Many properties are measured to indicate performance, and eventual failure, of a coating under these two broad categories. Monte Carlo simulations have shown success in predicting trends in macroscopic properties during exposure. The Central Limit Theorem (CLT) is applicable because damage made to a coating can come from the accumulation of a vast number of very small damage events. Application of the CLT to property equations has generated additional equations for the prediction of properties of a coating with exposure, including measurable properties such as gloss, color, fracture toughness, and contact angle. These equations, when fitted to measured data, provide in sight into the mechanisms of degradation processes, since the fitting parameters are physically based. They also offer a means to scale accelerated testing measurements to early field measurements of the property of interest for predicting lifetime in varied environments. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.