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

摘要

A novel phase change material (PCM), namely, comb polyurethane with polyethylene oxide segments as side chains (DMPEG-PU), was synthesized through the reaction between diethanolamine-modified monomethoxy polyethylene glycol (MPEG) with isophorone diisocyanate and 1,4-butanediol. The crystalline property, phase change property, and thermal stability were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TG), wide-angle X-ray diffraction (WAXD), scanning electronic microscopy (SEM), and polarization optical microscopy (POM). An accelerated thermal cycling test was then conducted to reveal the thermal reliability of the synthesized DMPEG-PU. The WAXD patterns and POM images showed that the synthesized DMPEG-PU possesses a completely crystalline structure and smaller spherulites compared with the pristine MPEG. The DSC results showed that DMPEG-PU (with 85% weight percentage of MPEG) is a typical solid-solid PCM with high thermal transition enthalpy of more than 120 J g(-1), which is higher than the thermal transition enthalpy of polyethylene glycol-based polyurethane. TG results showed that the synthesized DMPEG-PU exhibits satisfactory thermal stability.