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

对环境的关注已经推动了涂料行业技术的重大变革。为了减少挥发性有机化合物（VOC）释放到大气中的量，人们正在开发新技术，用水性涂料取代溶剂型涂料。我们的合作伙伴巴斯夫发明了一种基于环氧丙烯酸分散体的新型水性涂料，这种涂料有可能成为环保、坚韧和坚固的工业和汽车涂料的基础。这些分散体是在没有表面活性剂、盐或有机溶剂的情况下制备的，因此没有可能渗入环境的有害成分。有用的性能来自于涂料涂在基材上后的固化（交联）。为了优化涂层的性能，我们需要了解固化速率与聚合物链在涂层中的扩散速率之间的关系。涂料中的聚合物链扩散可以通过Winnik小组在过去15年中基于荧光共振能量转移（FRET）开发的技术来测量。我们建议在基于巴斯夫开发的这些新型环氧丙烯酸分散体的涂料上进行这些实验。了解烘烤温度如何影响不同聚合物成分的扩散和固化之间的竞争，将为巴斯夫的科学家提供知识，使他们能够优化涂料配方，特别是汽车涂料。

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.