Robust, self-healing polyurea/TPU elastomers

The development of self-healing materials is essential for advancing sustainable and durable technologies in fields such as soft robotics, wearable devices, and protective coatings. Polyurea (PU) and thermoplastic polyurethane (TPU) elastomers are particularly promising due to their combination of mechanical robustness, flexibility, and industrial processability. In this study, a PU/TPU elastomer was synthesized via the incorporation of polyurea/urethane segments into a commercial TPU matrix, producing a material with a dynamic, hydrogen-bonded network. FTIR analysis confirmed the presence of reversible interactions between urethane and urea groups, which underpin the material's intrinsic self-healing capability. The optimized PU/TPU formulation exhibits exceptional mechanical performance, with a tensile strength of 22.55 MPa, elongation at break of 872%, and toughness of 106.45 MJ m−3. Thermal self-healing tests at 120 °C demonstrated rapid recovery of mechanical properties, achieving healing efficiencies of 34.4%, 76.8%, and 84.2% after 2, 5, and 10 min, respectively. Cyclic tensile tests confirmed the durability and repeatability of self-healing behavior over multiple loading cycles. At the same time, optical microscopy and stress-relaxation experiments provided insight into the kinetics of bond reformation and chain reorganization. These results highlight the potential of PU/TPU elastomers as high-performance, self-healing materials that combine mechanical toughness, extensibility, and rapid repair.