Polyethylene Glycol/Polyurethane Acrylate-Based Flexible Phase-Change Film with Excellent Mechanical Strength and Reversible Optical Performance

The application of thermal energy storage (TES) technology in practical engineering has been limited by liquid leakage and material rigidity during phase change. In this study, we prepared novel polyethylene glycol (PEG)/polyurethane acrylate (PUA)-based flexible phase-change films (PCFs) using ultraviolet (UV) curing technology to solve these problems. The PCFs showed a desirable phase-change enthalpy (113.1 J/g), low leakage rate (1.70%), reversible optical performance, excellent shape stability, and superior flexibility. The tensile strength of the PCF was 5.00 MPa, and the elongation at break reached 1342.3%, which was five times higher than that of pure PUA, indicating outstanding flexibility and toughness. The as-prepared PCFs show great potential for future applications, such as incorporation into flexible electronic devices and temperature control systems.