Distribution of Al2O3 in PE/EVA blends and the thermal conductivity of PE/EVA/Al2O3 composites

This paper aims at dispersing nanoscale Aluminium oxide (Al₂O₃) in Polyethylene/Ethylene Vinyl Acetate copolymer blends (PE/EVA) to improve the thermal conductivity of the composites. Blends of PE and EVA were prepared at different PE/EVA ratio, and PE/EVA blends with co-continuous structure were obtained. PE/EVA/Al₂O₃ composites were prepared by dispersing different amount of Al₂O₃ into co-continuous PE/EVA blends. Scanning Electron Microscopy (SEM) was used to observe the morphology of PE/EVA/Al₂O₃ composites treated by selective solution extraction. The thermal conductivities and mechanical properties of PE/EVA/Al₂O₃ composites were investigated. SEM results indicated that Al₂O₃ was observed to selectively localize in PE phase. Moreover, the selective distribution of Al₂O₃ and the co-continuous structure of the composites were helpful in improving the thermal conductivity and mechanical properties, leading to a 20.9% increase of thermal conductivity of PE/EVA/Al₂O₃ composites in comparison to that of PE/Al₂O₃ composites.