UV-Curable Hybrid NIPU for Coating and 3D Printing Applications

Nonisocyanate polyurethane (NIPU) synthesis offers a safer and greener alternative to conventional polyurethane production. However, the poor reactivity between cyclic carbonates and amines limits their applications due to prolonged curing time. A hybrid approach was designed to address this challenge by incorporating glycidyl methacrylate into the amine-terminated NIPUs, enabling rapid UV-curing. The resulting methacrylate-functionalized NIPUs were fully cured within minutes under UV light, contrasting with thermal-curing NIPUs. Comprehensive characterizations of the cured films, including surface morphology, thermal properties, mechanical properties, and general coating properties, demonstrated that the formulation using bisphenol A diglycidyl ether-based cyclic carbonate and T403 amine exhibited the best overall performance, with 12.3 MPa tensile strength, 273.9 MPa Young’s modulus, 45.7% elongation-at-break, solid surface hardness, and excellent solvent resistance. This optimized NIPU was further explored for 3D printing, yielding fully cured, defect-free, and highly detailed structures after solvent removal and the addition of reactive diluent, with a gel content of 99.7%, which makes it applicable as a 3D printing material. The study highlights the potential of hybrid NIPU systems for advanced coating and customizable prototyping applications.