Development of a novel low-temperature curable one-component waterborne polyurethane acrylate coating with latent crosslinking for enhanced mechanical properties

A novel low-temperature curable, one-component (1K) Waterborne Polyurethane Acrylate (WPUA) coating with latent crosslinking properties has been successfully developed. The synthesized polyurethane features acrylate groups at the chain ends and unsaturated polyesters with double bonds derived from Maleic Anhydride (MA) in the soft segment. Polyethylene glycol 400-diacrylate (PEG 400-DA) acts as a latent crosslinker, allowing the system to remain stable during storage and initiate crosslinking upon thermal treatment at a significantly lower temperature of 80 °C, compared to traditional reported 1K systems, which typically require curing temperatures above 150 °C. The lower curing temperature makes this system particularly suitable for heat-sensitive substrates and applications where high temperatures cannot be applied. The latent crosslinking mechanism enhances the mechanical performance and thermal stability of the films, while maintaining ease of application and reducing energy consumption. The mechanical properties, thermal stability, and surface characteristics of the films were thoroughly evaluated using TGA, DSC, DLS, FTIR, RAMAN, NMR, SEM, and AFM. The results demonstrated improved mechanical strength, abrasion resistance, and thermal stability, making this low-temperature curable 1K WPUA system a promising candidate for environmentally friendly industrial coatings, especially on temperature-sensitive surfaces.