Thermal conductivity enhancement of form-stable phase-change composites by milling of expanded graphite, micro-capsules and polyethylene

Structured form-stable phase change composites were prepared by wet milling and hot-compaction of microencapsulated phase change material (MPCM), expanded graphite (EG) and high density polyethylene (HDPE). In the composites, MPCM serves as a latent heat storage material, EG as a heat transfer promoting agent and HDPE as a matrix. Scanning electron microscope (SEM) characterization reveals that MPCM particles kept undamaged with a uniform dispersion in the composites. Thermal conductivity of the composites with 20 wt% EG loaded could be enhanced by 22 times compared to HDPE/MPCM composites without EG. And thermal conductivity of the composite could be increased by 10 times at a loading of 10 wt% EG. •Form-stable phase change composites were prepared by wet millingand hot-pressing method.•MPCM particles disperse uniformly in the composites and are undamaged.•EG and GP both can act as the thermal enhancers of the composites.•EG is more effective than GP as a thermal enhancer in the composites.