Predicting Changes in Coating Properties during Weathering

Coatings are very important for controlling appearance of, and providing protection to, equipment and infrastructure components. The weathering durability of coatings is thus a very important determinant of the lifetime of the equipment. Coating properties may be related to how the surface or bulk of the coating are affected by the environment. Gaussian statistics or Monte Carlo simulations may be used to represent the accumulation of damage to a coating and thus its deterioration. The damage is due to random, repeated attack by ultraviolet radiation, moisture, acid pollution or heat. Properties such as gloss or fracture strength, may be calculated depending on how the surface of the coating is affected. Other properties, including corrosion protection may be related to changes in bulk properties. Results on clear and pigmented coatings, show that this use of these statistical approaches models the data well. There is potential for using properties that permit non-destructive monitoring, e.g. surface roughness, not only to predict other properties that would necessitate destructive evaluation, e.g. fracture strength but also to assess the severity of a particular environment or testing protocol.