Synthesis of UV-curing waterborne polyurethane-acrylate coating and its photopolymerization kinetics using FT-IR and photo-DSC methods

Environmentally friendly waterborne polyurethane-acrylate (WPUA) oligomers and ultraviolet curing WPUA films (UV-WPUA) were prepared. The thermal stability, solvent-resistance and mechanical properties of the films were investigated. FT-IR and photo-DSC methods were used to investigate the photopolymerization kinetics of the UV-WPUA films. The results showed that UV-curing films offered the optimum combination of properties when the polyether polyol (NJ-330), isophorone diisocyanate (IPDI), hydroxyethyl methyl acrylate (HEMA) and dimethylolbutanoic acid (DMBA) were used as the raw materials and the mass ratio of oligomer: monomer butyl acrylate (BA): photoinitiator was fixed at 66:30:4. Reaction kinetics of different photoinitiators systems were calculated by Kissinger equation and Crane equation, thus providing a theoretical guidance for the optimization of diluent and photoinitiator in UV-curing coating industry.