Preparation of exfoliated graphite-based polyethylene composites with enhanced thermal conductivity

Abstract

ABSTRACT Polyethylene/exfoliated graphite platelet (PE/EGP) composites with enhanced thermal conductivities were developed. EGP was obtained by zirconium dioxide-based ball-milling technique using urea as a modifying agent. The PE/EGP composites were prepared using a HAAKE rotational rheometer followed by a hot press operation. The structure and morphology of the EGP were characterized by X-ray diffraction, Raman spectroscopy, and Scanning electron microscopy. The thermal conductivities, mechanical properties, and crystallinities of PE and PE/EGP composites were systematically investigated. The thermal conductivities of PE/EGP composites increased with increasing amount of EGP. When the amount of EGP added was 10 wt%, the thermal conductivity of the composite reached 0.87 W/(m∙K), which was twice higher than that of PE. The tensile strength of the composite was more than doubled compared with that of PE matrix, while the elongation at break decreased. EGP could be uniformly dispersed in PE matrix as confirmed by SEM observation. DSC analysis showed that the addition of EGP to PE matrix increased the crystallization peak temperature and the crystallinity of the composite.