Polyrotaxane: New Generation of Sustainable, Ultra-Flexible and Form-Stable Phase Change Materials

The development of thermal energy storage materials is the most attractive strategy to harvest the solar energy and increase the energy utilization efficiency. Phase change materials (PCMs) have received much attention in this research field for several decades. Herein, we reported a new kind of PCM micro topological structure, design direction, and the ultra-flexible form-stable PCMs, polyrotaxane. The structure of polyrotaxane was fully confirmed by 1H Nuclear Magnetic Resonance, Attenuated Total Reflection-Fourier Transform Infrared and X-ray diffraction. Then the tensile properties, organic solvent resistance, thermal stability, fire safety and phase change energy storage properties of the films were systematically analyzed. The results showed that all the mechanical performance, organic solvent resistance, thermal stability and fire safety of PLRs were enhanced significantly compared to those of PEO. Nevertheless, the form stability at temperatures above the melting point of PEO significantly increased with the α-CD addition. Further with the high phase transition enthalpy and excellent cycle performance, the polyrotaxane films are therefore promising sustainable and advanced solid-solid phase-change materials for thermal energy storage.