Study on UV Curable Waterborne Polyurethane Modified by Epoxy Resin

Abstract

In this paper, UV curable waterborne polyurethane emulsions were prepared by fractional step method using toluene diisocyanate (TDI), polyethylene glycol (PEG, MW=1000), α,α-dimethylol propionic acid (DMPA), 2-hydroxyethyl methacrylate (HEMA) as raw material, and UV-WPUs were modified with epoxy resin. The effect of different content of epoxy resin on the viscosity, the water resistance, and other properties was investigated. The synthesized polyurethane structure was confirmed by the Fourier transform infrared spectroscopy (FTIR). The FTIR analysis identified that the target product was expected epoxy modified waterborne UV polyurethane. And with –COOH content increasing, the emulsion viscosity of the WPU increased and the water absorption of the films increased; with epoxy content increasing, the viscosity of the WPU emulsion increased and the water resistance of the films was improved.