Review of self-healing strategies contributing to sustainable resilience in polymer composite systems

Self-healing polymers, which include capsule-based, vascular, and intrinsic healing processes, represent a significant advancement in materials research. Capsule-based techniques are inspired by nature and employ microcapsules for controlled release, demonstrating potential in various applications. Vascular self-healing mirrors nature’s capillary systems by using interconnected channels for localized repair, extending its use beyond concrete fracture restoration to composite polymeric materials. Intrinsic healing is based on polymers with inherent restorative capabilities activated by low-level energy sources, providing resilience and self-healing. Experimental research utilizing optical microscopy, FTIR, TGA, and flexural tests revealed real-time healing, chemical composition, and thermal stability information. Numerous encapsulation methods show versatility, such as coaxial electrospinning and solution blowing. It is still quite difficult to balance mechanical strength and healing powers, which emphasizes how crucial it is to keep trying to do so. The healing efficiency data reported in tables reveal the potential of both intrinsic and extrinsic self-healing processes to restore essential material properties, with certain systems obtaining efficiencies of more than 70%, depending on the polymer matrix and healing strategy used. Long-term durability and adaptation difficulties persist despite advances. Self-healing polymers have the potential for strong, long-lasting, and flexible solutions that will influence materials engineering in the future as research progresses. The novelty of this review lies in its integrated comparison of capsule-based, vascular, and intrinsic self-healing strategies, with emphasis on how their healing mechanisms, efficiencies, and experimental validations collectively contribute to strong, long-lasting, and sustainable polymer composite systems.