Dual-dynamic crosslinked polyurethanes with synergistic mechanical reinforcement, self-healing, recycling and photoluminescence

Abstract

Self-healing polyurethanes that combine 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. 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 m⁻³ and excellent resilience. Due to the synergistic effect of dynamic hydrogen bonds and ionic bonds, it also exhibits excellent self-healing (88.94% healing efficiency at 80 °C for 12 h) and reprocessability (92% recycling ratio at 100 °C under 5 MPa for 5 min). Notably, HIPU-2 also displays distinct photoluminescent characteristics, broadening its potential applications in the fields of crack detection and anti-counterfeiting.