Synthesis and investigation of form-stable myristic acid based composite phase change material containing styrene ethylene butylene styrene with enhanced properties for thermal energy storage

To overcome the challenges of low thermal conductivity and leakage of fatty acid based phase change materials (PCMs), a high-efficiency form-stabilized composite, with the use of styrene ethylene butylene styrene (SEBS) as structure material, was prepared and investigated in this work. The myristic acid (MA) was used as PCM and graphite was employed as thermal conductivity enhancer to improve composite thermal conductivity. A series of characterizations were performed to investigate the composite microstructure, chemical compatibility and thermal properties. Furthermore, the thermal conductivity and mechanical strength enhancement of the composite were evaluated by dispersing of high density polyethylene (HDPE). The results showed an excellent chemical compatibility in the composite. The MA can be uniformly dispersed in the SEBS matrices and 15 wt% SEBS endowed the composite with the capacity to maintain structure stabilization. The Differential Scanning Calorimetry and Laser Flash Analyser results revealed that the MA/SEBS/graphite composite with a mass ratio of 85:15:10 presented a constant melting temperature around 53 °C, high latent heat of 150.33 kJ/kg and high thermal conductivity of 0.655 W/m·K. The composite thermal conductivity and mechanical strength can be further enhanced by adding of HDPE and a loading of 5 wt% HDPE achieves the enhancement of the composite thermal conductivity and mechanical strength respectively by 25.4% and 16.4%.