Multiple H-bonds induced mechanically robust vat photopolymerization 3D printing poly(urethane-urea) elastomers

Vat photopolymerization (VP) elastomers show great promise across various fields, yet they face significant challenges in achieving adequate mechanical strength, elasticity, and durability due to incomplete polymerization and weak interfacial bonding between printed layers. In this study, we introduce high-performance poly(urethane-urea) elastomers (PUEs) utilizing a dual cross-linked network (DCN) strategy compatible with VP 3D printing. This innovative approach enhances mechanical properties by incorporating multiple hydrogen-bonded urethane and urea groups. The presence of multiple hydrogen bonds facilitates energy dissipation under external mechanical stress and improves interfacial interlocking, while the covalent cross-linked network provides stability and flexibility during deformation. The resulting elastomer exhibits a tensile strength of 28.30 ± 1.10 MPa, a recovery strain of approximately 300%, and a fracture energy of 22.90 ± 4.20 kJ m^-2. As a proof of concept, we demonstrate the rapid fabrication of 3D-printed stents with intricate architectures, outstanding load-bearing capabilities, and excellent biocompatibility. This strategy not only paves the way for the development of mechanically robust, complex-structured PUEs but also broadens their application scope in engineering and biomedical fields.