A novel one-step ultraviolet curing fabrication of myristic acid-resin shape-stabilized composite phase change material for low temperature thermal energy storage

In this work we present for the first time a simply, fast and efficient process for the fabrication of form-stable composite phase change material (PCM) by ultraviolet (UV)-curing technique. Simply by UV-curing of the PCM with a desired UV curable carrier for several minutes, a neoteric UV-cured composite that suitable for low temperature thermal energy storage (TES) can be fabricated. The feasibility of such a novel technique is demonstrated by investigating a case of myristic acid (MA) dispersed into a UV curable resin containing poly-urethane acrylate (PUA). The results show that a crosslinked structure is formed in the composite after UV-curing due to the occurrence of photochemical reaction, which offer sufficient paths to accommodate the PCM, endowing the composite with the great ability to maintain the structure stabilization and prevent the liquid leakage. A good physical and chemical compatibility has been achieved in the composite and 40 wt% of UV -curing resin grants the composite optimum formula at which a melting temperature of 52 degrees C and an energy storage density over 210.8 kJ/kg at temperature ranged 25-100 degrees C are obtained. The results also reveal that the material mechanical strength can be linked to the UV-curing duration. For a given V-curing time of 5-30 mins, the composite mechanical strength is measured over 25-34 MPa, almost over twice as high as that of high -density polyethylene (HDPE) and styrene ethylene butylene styrene (SEBS) based composites. Owing to the high shape strength and excellent thermal cycling performance, such UV-curable composites can be utilized for modular design of TES devices, and also be used to precisely and directionally produce TES devices through additive manufacturing. This work exploits a new perspective for the energy-saving and time-effective fabrica-tion of shape stabilized composite PCMs for low temperature thermal energy storage.

Automated summary

In this study, a novel technique of UV-curing was used to fabricate a form-stable composite PCM suitable for low temperature TES. The UV-curing process resulted in the formation of a crosslinked structure in the composite, providing sufficient paths to accommodate the PCM and preventing liquid leakage. The composite demonstrated good physical and chemical compatibility, with the optimum formulation achieving a melting temperature of 52℃ and an energy storage density of 210.8 kJ/kg. The mechanical strength of the composite was found to be dependent on the UV-curing duration.