Constructing intrinsic solid phase change materials with reprocessability and thermal energy storage through multiple hydrogen bonds and acetals

Thermal management in flexible phase change materials (PCMs) for electronic devices necessitates a delicate balance between energy storage capacity, mechanical properties and reprocessability within complex application environments. However, the structural design of most flexible phase change materials only focuses on a single functional requirements and fails to meet the demands for phase change thermal energy storage materials and thermal management devices with multiple different performances. Therefore, we propose a simple and cost-effective strategy is proposed to fabricate intrinsic solid-solid phase change materials (SSPCMs) that balance heat storage, mechanical strength and reprocessability. We prepared a polyurethane matrix using high molecular weight PEG, which is more easily crystallized, and a bio-based acetal diol derived from furfural and 1,6-hexanediol. The introduction of bio-based acetal diols improves energy storage capacity and efficiency. In addition, the matrix contains multiple H-bonds, which act as strong physical crosslinks to enhance the mechanical properties of the flexible PCM. The resultant high-performance phase change materials (HFPCMs), with a polyethylene glycol (PEG) content of 80 wt%, show remarkable latent heat capacity of 134.43 J g −1 , a tensile strength of 1034 %, high thermal stability (no significant shape change below 160 °C), and good reprocessability. In the cyclic thermal stability test, it has good reversible stability and cyclic sustainability. Overall, this work provides a new method to development of intrinsic SSPCMs with high energy storage capacity, good mechanical properties, and reprocessability, offering significant potential for advanced thermal management in electronic devices.