EFFECT OF MILLED GRAPHITE COMPOSITION ON THE MECHANICAL PROPERTIES AND MORPHOLOGY OF HIGH DENSITY POLYETHYLENE (HDPE)/GRAPHITE COMPOSITE
Abstract
High density polyethylene (HDPE)/graphite composites were made by melt blending and polymer injection process with milled graphite as a filler. The effect of milling time and composition of milled graphite to physical and tensile properties of composites were investigated. The microstructure evolution of the milled graphite and fracture surface of the HDPE/graphite composites were characterized by X-ray diffractometer (XRD) and scanning electron microscope (SEM). XRD analysis showed that the graphite peak and crystallite size of graphite decreased from 17.82 nm to 15.15 nm with increasing of milling time. The reduction in fragmented size of graphite was also observed in SEM micrograph with increment of milling time. The mechanical properties study of HDPE/graphite composites represents the considerable effect of milled graphite on the increasing of Young's modulus. For sample that filled with 4 wt.% of 50 hours milled graphite, the Young’s modulus was 1295 N/mm2, a 24 % enhancement than the HDPE without graphite filler. The addition of milled graphite has improved mechanical properties of HDPE/graphite composite and suitable as a candidate for structural application.
