A route of polyethylene glycol-based phase change heat storage wood with AlN as the thermal conductive filler

Abstract

Wood is a great natural material with good energy storage and temperature adjustment for the energy crisis. In this study, wood was delignified, and the PEG-based eutectic polymer (PGMA) was impregnated into the delignified wood, and styrene (SM) grafted AlN was selected as thermal conductive filler to synthesize a stable phase change heat storage wood. The result shows that the styrene (SM) polymerized on the surface of AlN to form polystyrene (PS), and the dispersion of AlN was enhanced. The thermal stability and loss resistance of PCES-Wood are improved for the penetration of PS-AlN into the cavities, which is attributed to the PS-AlN playing a “limiting” role in the crystallization of PGMA. When the content of PS-AlN is 6%, the thermal conductivity of PCES-Wood reaches 0.5148 W/(m·K). 4% PS-AlN-PCES@Balsa has the lowest undercooling and heat loss rate, and the melting enthalpy and solidification enthalpy reach 125.60 J/g and 120.30 J/g, respectively. The phase change temperature range is between 19.59 and 33.87 °C, which is in the comfortable temperature range for humans. Under the illumination of the simulated solar light source, the surface temperature of PS-AlN-PCES@Balsa rises rapidly and shows a lasting heat storage capacity at low temperatures compared with the original wood. After 200 cold and hot cycle tests, the phase change enthalpy of PS-AlN-PCES@Balsa is still high, and there is a slight leakage phenomenon. The phase change wood prepared in this study shows that it is a potential material to store and release solar energy in practical applications.