Dual-dynamic Crosslinked Polyurethanes with Synergistic Mechanical Reinforcement, Self-Healing, Recycling and Photoluminescence

Abstract

Self-healing polyurethanes that integrate robust mechanical properties with stimuli-responsive functionalities represent a frontier in advanced material design. However, achieving synergistic enhancement of mechanical strength, rapid self-repair, and additional optical properties in a single polyurethane system remains challenging due to conflicting structure-property relationships. In this work, we report a series of dual-dynamic crosslinked polyurethanes (HIPUs) synthesized by simultaneously introducing reversible hydrogen bonds and ionic interactions. The optimized HIPU-2 exhibits robust mechanical properties with a tensile fracture stress of 25.68 MPa, an elongation at break of 802 %, a toughness of 68.02 MJ/m3 and excellent resilience. Due to the synergistic effect of dynamic hydrogen bonds and ionic bonds, it also presents excellent self-healing (a healing efficiency of 88.94% at 80 °C for 12 h) and reprocessability (a recycling ratio of 92% at 100 °C under 5 MPa for 5 min). Notably, the HIPU-2 also displays distinct photoluminescent characteristics, broadening its potential applications in crack detection and anti-counterfeiting fields.