Synthesis and thermal properties of novel solid-solid phase change materials with comb-polyurethane block copolymer structure for thermal energy storage

A series of novel comb-polyurethane phase change materials (CP-PCMs) with poly(ethylene glycol) (PEG) as side chain were synthesized through the reaction between diethanolamine-modified methoxypolyethylene glycol (DMPEG) with diisocyanate and 1,4-butanediol (BDO). The structure and phase change property of CP-PCM were characterized by gel permeation chromatography (GPC), H-1 nuclear magnetic resonance (H-1 NMR), Fourier transform infrared (FTIR) spectroscopy, and polarization optical microscopy (POM). The H-1 NMR and FTIR spectra confirmed the success synthesis of CP-PCM. The POM images showed that CP-PCM possessed a completely crystalline structure and smaller spherulites compared with the pristine methoxypolyethylene glycol (MPEG). The influence of phase change property of CP-PCMs was also investigated using differential scanning calorimetry (DSC). The results showed that the CP-PCM synthesized using isophorone diisocyanate (IPDI) or 1,6-hexamethylene diisocyanate (HDI) as diisocyanate and MPEG with molecular weight of 5000 as soft segment possessed optimal phase change property. In addition, the phase change enthalpy and temperature of CP-PCMs decreased as the weight percentage of MPEG decreased. (C) 2017 Elsevier B.V. All rights reserved.