UV-curable non-isocyanate polyurethane/acrylate (NIPUA) hybrid coatings via transurethanization: A sustainable approach

(Meth)Acrylic end-capped non-isocyanate polyurethanes (NIPUAs) were synthesized via transurethanization. The resulting prepolymers were then blended with acrylic monomers to produce UV-curable hybrid urethane/acrylic coatings. The structural characterization of the prepolymers before curing was performed using Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance ( 1 H NMR), and carbon nuclear magnetic resonance ( 13 C NMR). Thermal properties were evaluated using differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA). The curing reaction was analyzed by “in situ” photo FTIR and photo calorimetry, achieving high conversion within a few seconds. In the cured samples, the incorporation of NIPUA into acrylate matrix resulted in a decrease in the glass transition temperature (T g ), providing enhanced flexibility. All the coatings showed good water and solvent resistance, as well as good adhesion to pine wood. The hardness increased with the acrylic content of the coatings. The results show that the NIPUA/acrylate blends can be tailored according to the requirements of specific coating applications, highlighting their potential as safer and environmentally friendly alternatives to isocyanate-based polyurethane coatings. • Methacrylic end capped NIPUA polymers via transurethanization reaction. • Blends of the NIPUA with acrylic monomers and photopolymerization. • Fast curing reaction studied by FTIR and Photo-DSC. • Incorporation of NIPUA into acrylate decreases Tg and enhances flexibility. • Good coating properties for all the samples.