Preparation and properties of dual-cure polyurethane acrylate

Dual-cure polyurethane acrylates (PUA) with different double bonds content were synthesized by using aliphatic polyisocyanate and 2-hydroxyethyl acrylate (HEA). The molecular structures were identified by Fourier transform infrared (FTIR) spectrum and nuclear magnetic resonance (NMR). Molecular weight (Mw) and glass-transition temperature (Tg) of PUA were measured by gel permeation chromatography and DSC, respectively. The pendulum hardness, pencil hardness, flexibility and abrasion resistance properties of dual-cure system were tested, the results indicated that the pendulum hardness, pencil hardness, and MEK resistance increased, but the flexibility reduced with the double bonds content increased. The mechanical properties of dual-cure system were greatly improved after the heat treatment.