Reliable phase‐change polyurethane crosslinked by dynamic ionic‐bond crosslinking for thermal energy storage

Abstract

ABSTRACTThe fabrication of phase‐change materials (PCMs) for thermal energy storage is of great significance, since they combine the sustainable development of energy and human comfortable. Herein, a dynamically crosslinked PCM was successfully fabricated by the blending of complementary polyurethanes bearing carboxylic acid and tertiary amine through reversible ionic bonds via the acid–base reaction. The resultant PCM exhibited good crystalline property, which was confirmed by wide‐angle X‐ray diffraction and polarizing optical microscopy. Differential scanning calorimetry characterizations suggested that the prepared PCMs could reversibly store and release latent heat during heating and cooling process. The presence of physical crosslinks in PCM could maintain shape stable and had no deteriorate effect on the value of latent heat. Therefore, a high latent heat of 70 J/g was obtained within the temperature range of 13.2–45.4 °C. This good thermal storage ability remained constant even after 100 consecutive heating/cooling cycles. Thermogravimetric analysis results provided distinct evidence that the prepared PCM has an outstanding thermal stability with the onset decomposition temperature higher than 250 °C. The combined thermal storage ability and thermal reliability endow the PCM promising application as solar energy storage, waste heat utilization, and thermal protection coatings or adhesives. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48213.