Understanding polymer diffusion in thermoset epoxy-based waterborne coatings and its influence on final film properties

点击翻译按钮获取中文摘要

Concern for the environment has been driving major changes in technology in the coatings industry. To reduce the amount of volatile organic compounds (VOC's) released to the atmosphere, new technology is being developed to replace solvent-based coatings with water-based coatings. Our partner BASF has invented a new type of waterborne coating based on epoxy-acrylic dispersions that has the potential to serve as the basis for environmentally friendly tough and robust industrial and automotive paints. These dispersions are prepared without surfactants, salts, or organic solvents and thus do not have harmful components that can leach into the environment. The useful properties come from curing (cross-linking) of the coating after it is applied to a substrate. In order to optimize the properties of the coating, one needs knowledge of how the curing rate compares to the rate of diffusion of polymer chains in the coating. Polymer chain diffusion in coatings can be measured by techniques developed in the Winnik group over the past 15 years based on fluorescence resonance energy transfer (FRET). We propose to carry out these experiments on coatings based on these new epoxy-acrylic dispersions developed at BASF. Understanding how baking temperature affects the competition between diffusion and cure for different polymer compositions will provide knowledge to scientists at BASF that will enable them to optimize their coatings formulations, particularly for automotive coatings.