Unsaturated polyester resin supported form-stable phase change materials with enhanced thermal conductivity for solar energy storage and conversion

Abstract

Solar energy absorption, conversion, transportation and storage are crucial for high-efficiency solar thermal utilization. It is positive and promising to develop novel phase change materials (PCMs) with good shape stability, excellent photo-absorption and thermal-physical properties in the practical solar thermal application. Polymer supported PCMs with good heat transfer performance show an extensive application prospect. This research introduces a straightforward and practical strategy to prepare flexible poly (ethylene glycol) (PEG) form-stable phase change materials (FSPCMs) by taking cross-linked unsaturated polyester resin as skeleton and expanded graphite (EG) as thermal conductivity additive. The results show the FSCMs have excellent stability, thermal reliability and can be kept from leaking at 80 °C. The efficiency of photo-thermal conversion of FSPCMs doped with 7 wt % EG is up to 93.3%. The thermal conductivity is 1150% higher than PEG. Comparing to PEG, FSPCMs doped with 7 wt % EG can save time of 67.1% and 51.4% during the heating and cooling processes, respectively. The unsaturated polyester resin as common industry materials will provide more possibility for FSPCMs with enhanced thermal conductivity in practical solar thermal application.