Synthesis and properties of hyperbranched polyurethane acryiate used for UV curing coatings

摘要

Dendritic and hyperbranched polymers have different structures to their linear polymer counterparts that confer interesting properties such as high solubility, low viscosity and high number of reactive groups. They therefore have the potential to modify the properties of epoxy acryiate coatings, which have good strength and solvent resistance, but the coatings tend to be britde. In this paper, a hyperbranched polyurethane acryiate with high functionality (HPUA) is prepared by a two step process: (1) the preparation of a hyperbranched polyurethane with terminal hydroxy groups from the reaction of diethanolamine with isophorone diisocyanate (IPDI), in the presence of dibutyltin dilaurate, until all the isocyanate groups were consumed; (2) the reaction of the semi-adduct urethane monoacrylate (IPDI-hydroxyethyl acryiate) with the hydroxy-functional polyurethane.