Reprocessable, biodegradable polyester-based solid-solid phase change materials networks from dynamic ionic crosslinking with high latent heat capability

Thermosetting polyethylene (PEG)-based solid-solid phase change materials networks (PCMNs) have high latent leat and form stability from the covalent crosslinking, yet they remain a great challenge in reprocessing and recycling of PCMNs without compromising a high latent heat above 100 J/g. Herein, the polyester-based solid-solid PCMNs with PEG as phase change component were synthesized via ionic crosslinking between the linear multiple carboxyl-functionalized phase change materials (CPCMs) polyester and zinc cations. The CPCMs were synthesized via polyesterification reaction between pyro-mellitic dianhydride (PMDA) and diol containing PEG and ethylene glycol, meanwhile forming multiple carboxyl along molecular chains. The dynamic ionic bonds and hydrolysable ester bonds endowed PCMNs with the reprocessability and biodegradability, respectively. PCMNs had the Delta H = 120 J/g with PEG weight fraction of similar to 0.91 and concentration of carboxyl of similar to 0.26 mmol/g. Also, PCMNs had good phase change ability, thermal stability and thermal reliability before and after thermal cycling and reprocessing. The robust approach enabled the combination of the reprocessing ability and high latent heat of PCMNs by ionic crosslinking. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

In this study, polyester-based solid-solid PCMNs with high latent heat and reprocessability were synthesized through ionic crosslinking, providing a new approach for the reprocessing and recycling of PCMNs. The dynamic ionic and hydrolysable ester bonds endowed PCMNs with both reprocessability and biodegradability, while maintaining good phase change ability and thermal stability.