Abstract:

Solid-solid phase change materials (SSPCMs) are a new class of materials capable of efficiently absorbing and releasing thermal energy through a reversible phase change process while maintaining solid-state properties. These materials have attracted extensive attention from the scientific research community owing to their small volume change during phase change, absence of any leakage phenomenon at high temperatures, and excellent mechanical properties. Polymeric SSPCMs with polyethylene glycol (PEG) as the phase-transition unit have shown great potential for applications in various key areas such as energy storage, temperature regulation, and thermal management. This is because they possess unique advantages such as high energy storage density, excellent cycling stability, and tunable phase transition temperature. This study focuses on the research progress of PEG-based SSPCMs in recent years, summarizing their classification and chemical preparation methods. Considering their defects such as thermal conductivity, flame retardancy, and poor recyclability, we focus on optimizing and modifying their properties to broaden their applications. This study also summarizes the research progress on their potential applications in the fields of thermal management of batteries, electronic devices, and flexible wearables, as well as the thermal energy storage of solar energy. Finally, the current challenges affecting PEG-based SSPCMs were analyzed. Future research should be devoted to the research and development of environmentally friendly and multifunctional SSPCMs, as well as to improving the comprehensive performance, reducing the cost, and enhancing the feasibility of SSPCMs. Another research avenue is to explore the potential of their application in a wider range of fields to further promote their practical applications.

Key words: polyethylene glycol, solid-solid phase change, phase change materials, polyurethane, composites