Shape-stable and smart polyrotaxane-based phase change materials with enhanced flexibility and fire-safety

Abstract

With the high performance of intelligent electronic machines and the popularity of flexible and foldable devices and high-speed/large capacity 5G communication, the market demand for flexible heat storage and smart temperature control materials are gradually rising. Therefore, phase change materials (PCMs) have received much attention in the related energy storage and temperature control field. As the amount of PCM increases, so do the fire safety concerns associated with their applications. Therefore, the development of improved the flexibility and fire safety for advanced PCMs is imperative. In this work, we reported a pentaerythritol phosphate modified sustainable polyrotaxane as PCMs for thermal energy storage and thermal management. The structure of pentaerythritol phosphate was adequately confirmed by 13C NMR, 31P NMR and ATR-FTIR. Subsequently, the tensile properties, fire safety, phase change performances and shape memory properties of the PCMs were fully analyzed. The results showed that all the flexibility, fire safety and thermal conductivity of modified polyrotaxanes were enhanced remarkably compared to those of pristine polyrotaxane. Further with the high form stability, and excellent cycle stability, the modified polyrotaxanes are therefore promising sustainable and fire safe shape-stable PCMs for thermal energy storage. Notably, its ultra-high flexibility (with elongation higher than 1000%), processing ability, excellent form-stability, enhanced fire-safety (with UL94 V-0 rating and LOI of 33.0%) and thermal conductivity (0.47 W m−1 K−1) provide a practical way for the safe and intelligent heat treatment for some electronic devices, such as solid-state disk.