PBT/adipic acid modified PEG solid-solid phase change composites

The complicated preparation process and difficulty of recycling were serious obstacles to the widespread use of solid-solid phase change materials (PCMs). Herein, we reported a novel thermoplastic solid-solid PCMs prepared by a facile one-step feeding method. In this study, the esterification and transesterification among the molten mixture of PBT, PEG and adipic acid were conducted to prepare thermoplastic PEG/PBT/Adipic acid copolymer-based PCMs. Adipic acid, as an auxiliary encapsulation agent, could prevent effectively PEG leakage of PEG/PBT/Adipic acid copolymer-based PCMs with high PEG and low PBT content during the phase change process. For PCM-6 containing 91 wt% PEG, 8 wt% PBT and 1 wt% adipic acid, there were no changes in the shape and chemical structure after multiple thermal cycles. The TG results presented that the initial thermal degradation temperature of PCMs-6 was above 200 °C, which was much higher than the processing and working temperature of PCMs-6. The latent heat of PCMs-6 could reach 136.8 J/g, showing great potential for energy storage, especially in the field of green buildings.