Enabling Supramolecular Phase Change Materials with High Latent Heat Ability and Recyclability

Abstract

The design of supramolecular phase change materials (SPCMs) with both high latent heat and recyclability remains challenging via multivalent interactions such as hydrogen bonds. Herein, the SPCMs are developed by integrating linear polyethylene glycol (PEG) as phase change functional components into physically cross-linking networks formed via the multivalent interactions between linear supramolecular polymers of polyurethane, enabling a combination of high latent heat of 143.1 J/g and solvent-assisted recyclability. The SPCMs presented the tunable latent heat (87.3−143.1 J/g) and phase change temperature (36.4− 59.8 °C) via the tunable molecular weight and content of linear free PEGs. The SPCMs had much smaller spherulite size than the free PEG counterparts due to the effect of the supramolecular polymer on the crystallization behaviors of free PEGs in SPCMs. The supramolecular polymer network endowed the SPCMs with good thermal reliability, thermal stability, and nonleakage properties. Significantly, the solvent-assisted recycle of SPCMs were enabled via completely dissolving the SPCM in solvent and then removing the solvent. The design of SPCMs nicely realizes the combination of high latent heat and recycling, which will extend the application range of phase change materials.