A facile preparation of UV-cured films from waterborne unsaturated polyester via click reaction

Due to the deterioration of the environment, the environmental protection has received more and more attention from the world. Various countries have established regulations to strictly limit the emission of organic volatiles (VOC) in paints. Solvent-based paints contain a large amount of VOC components, which not only pollutes the environment and wastes resources but also endangers people's health. Waterborne polyester coatings as representative waterborne coatings have become the development direction of coatings. In this study, a novel waterborne unsaturated polyester was synthesized by melt polycondensation and its water solubility was regulated by changing the amount of sodium sulfonate group. Then, a series of UV curable polyester networks were obtained utilizing the waterborne unsaturated polyester and multifunctional thiols via thiol-ene click reaction. The water resistance, gel content and mechanical properties of the films were characterized. It was found that the UV-cured films exhibited excellent physical properties including adhesion (1), pencil hardness (5 H), water resistance and contact angle (105.36). This shows that it is feasible to prepare high-performance UV cured films based on thiol-ene click chemistry.