Recyclable Solid–Solid Phase Change Materials with Excellent Reprocessing Properties Based on Dynamic Disulfide Bonds

Phase change materials (PCMs) with energy-saving and sustainable energy potential are widely available for energy storage technologies. At present, chemical cross-linking is often constructed to form solid–solid phase change materials (SSPCMs) to avoid leakage during the phase change process, but its permanent cross-linked network cannot be reprocessed, resulting in nonrecyclable materials with very high environmental impact. Herein, we prepare a series of poly(ethylene glycol) (PEG)-containing reprocessed solid–solid phase change materials (RSSPCMs) based on dynamic disulfide bonds, which were in the solid state even at high temperatures. These RSSPCMs had high latent heat with a maximum value of 100.2 J/g, which exhibited remarkable thermal storage capacity in addition to excellent solar-thermal conversion capacity. Interestingly, the introduction of dynamic disulfide bonds in the molecular structure provided RSSPCMs with excellent self-healing properties and recyclability. Broken RSSPCM samples could heal under thermal-induced and infrared radiation-induced reprocessing. Importantly, the chemical structure, crystallization behavior, and phase transition ability of RSSPCMs could also remain unchanged after multiple recycling. Designing RSSPCMs based on dynamic disulfide bonds is important for achieving the efficient utilization of solar energy and environmental protection.