Abstract:
UV curable waterborne polyurethane (WPU) coatings were prepared by serial steps 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-WPU was modified with 3-triethoxysilylpropylamine in this paper. The effect of different DMPA content, organosilicon addition and the degree of neutralization on the viscosity of UV-WPU emulsion and the water absorption properties of the curing film was investigated. The synthesized polyurethane structure was confirmed by the Fourier transform infrared spectroscopy (FTIR). The FTIR analysis identified that the target product be expected waterborne UV polyurethane, and with –COOH content increasing, the emulsion viscosity of the WPU increased and the water absorption of the films increased; and the organosilicon modified PU improved the crosslinking density, the viscosity of the WPU emulsion increased rapidly and the water absorption of the films decreased.