Recent Advances in Self-Healing Hybrid Polyurethanes: From Molecular Design to Intelligent Functional Materials

Self-healing materials (SHMs) have attracted the attention of scientists as they represent a diverse type of novel functional materials in the field of smart polymers. They are capable of repairing physical damage, resulting in an extended service life of materials. Among various polymers, polyurethanes (PUs) have emerged as a highly versatile class of polymeric materials due to their intrinsic structural tunability, mechanical robustness, and compatibility with dynamic chemical motifs. However, it is still challenging to achieve excellent mechanical properties and excellent healing efficiency at the same time. To address this challenge, dynamic covalent bonds and dynamic non-covalent interactions have been incorporated into polyurethane networks with varying degrees of success. Consequently, hybrid strategies have emerged as a promising approach. Such hybrid systems can be achieved through the integration of dynamic covalent bonds and reversible non-covalent interactions within a single polymer network, enabling synergistic optimization of mechanical strength, adaptability, and healing efficiency. Alternatively, hybrid polyurethane composites can be developed through the incorporation of functional nanofillers and additives (including carbon-based materials, two-dimensional materials such as MXenes, where M represents a transition metal and X represents carbon or nitrogen, metal–organic frameworks (MOFs) and covalent organic frameworks (COFs)), which impart additional functionalities and broaden the application scope of polyurethane systems. This review summarizes recent progress in self-healing hybrid polyurethanes, highlighting molecular design strategies, structure–property relationships, and emerging approaches toward intelligent multifunctional materials.