Coatings update: scientific advances

The degradation of coatings is, of course, a major area of interest for paint chemists. One of the coatings that degrades, much to the consumer's despair, is automotive coatings. The degradation of an acrylic‐melamine, cross‐linked coating containing finely dispersed pigment, metallic flake, and other additives was studied by English and Spinelli (Organic Coatings and Applied Polymer Science Proceedings, preprints of papers presented by the Division of Organic Coatings and Plastics Chemistry at the American Chemical Society, 185th National Meeting, Seattle, Washington, March 20–25, 1983, p. 733) using diffuse reflectance infra‐red spectroscopy. They found that the degradation is facilitated near the surface by ultra‐violet light and that there is a cleavage of the nitrogen‐carbon bond on the methoxymethylamino moities. Much of the degradation appears to take place at the surface level and degradation of bonds does not lead to significant self‐condensation of the degraded materials. The authors indicate that they are currently using MMR techniques to identify the products of degradation.