UV-Curable, Self-Healing and Rigid Polyurethane-Urea Acrylate Elastomers Reinforced with Zirconium Phosphate Nanosheets

Elastomers synthesized by vat photopolymerization suffer from poor mechanical properties due to low molecular weight and limited chain entanglement, while increasing entanglement improves toughness at the cost of resin viscosity and printability. This study proposes a strategy combining molecular architecture design and nanosheet integration, successfully achieving high-precision (100 μm) 3D printing of ultraviolet UV-curable polyurethane-urea acrylate (PUUA) elastomers with excellent comprehensive properties. Specifically, a chain extender containing urea bonds was first introduced into polyurethane prepolymer, and then mixed with a photoinitiator, reactive diluent and zirconium phosphate (ZrP) nanosheets, to formulate the UV-curable PUUA/ZrP resin. The urea bonds not only enhanced the mechanical properties of the material but also established a dynamic hydrogen bond network capable of self-healing, achieving a postrepair tensile strength of 27.1 MPa with a recovery efficiency of 84.6%. Characterization, including scanning electron microscope (SEM), atomic force microscope (AFM), and Fourier transform infrared (FTIR) spectroscopy, revealed that the uniform dispersion of ZrP nanosheets; and their interfacial synergistic effects further improved the mechanical strength, impact resistance, and environmental stability of the composite. The optimal composite exhibited a tensile strength of 32 ± 0.9 MPa, in comparison with that of pure PUUA (25 ± 1 MPa), along with good resilience, fatigue resistance, and the ability to form complex structures, demonstrating potential for high-performance UV-curing 3D printing applications.