Enabling High-Toughness Self-Healing Phase-Change Materials via a Dynamic Supramolecular Network

Conventional solid–solid phase change materials (PCMs) based on covalent cross-linking effectively address leakage issues but suffer from a lack of high toughness and self-healing capability. To overcome these limitations, a high-strength, toughness self-healing phase change material (SHPCM) was developed by constructing a dynamic supramolecular network. This was achieved through the synergistic combination of reversible disulfide bonds and hierarchical hydrogen bonds within a polyethylene glycol (PEG)-based polyurethane framework. The resulting material exhibits a solid–solid phase transition with a high latent heat of 98.4 J·g –1, along with superior mechanical properties, including a tensile strength of 23.28 ± 1.45 MPa, an elongation at break of 1468.02 ± 105.36%, and a fracture energy of 238.27 ± 35.31 MJ·m –3 . It also demonstrates high thermal reliability and stability. Critically, the dynamic supramolecular network endows the material with outstanding self-healing performance, achieving an efficiency of 94.93%. This unique integration of thermal energy storage, robust mechanical strength, and recyclability positions this SHPCM as a promising multifunctional material for advanced thermal-management applications, with potential for modular construction and extended service life.