Effects of additives on the performance of two-component waterborne polyurethane coatings

The effects of various additives and solvents on a coating’s performance in a two-component waterborne polyurethane coating system are studied using a statistical experimental design method. Using a blocked arrangement of fractional factorial design matrices, six different independent variables, including the use of different additives, catalysts, as well as solvents at different levels, were examined for their effects on various coating performance parameters, such as gloss, hardness, viscosity, and chemical resistance. Statistical analysis revealed several significant effects of these additives on the coating performances. Most importantly, several two-factor interactions between additives were also found to significantly influence the performance properties of the coating. These interactions could be very difficult to detect using traditional one-at-a-time experimental approaches. The information obtained from this study could be used for designing coating systems with superior performance properties. Presented at the 26th International Waterborne, High-Solids and Powder Coatings Symposium, February 10–12, 1999, New Orleans, LA. Coatings and Colorants Division, 100 Bayer Rd., Pittsburgh, PA 15205-9741.