Based on the literature survey, there is no any evidence of study concentrated on polyethylene-alumina nanocomposites. Thus, the main goal of this study is to fabricate polyethylene-alumina nanocomposites by high energy ball milling as a new method. Also it is tried to elucidate the role of both ball milling and alumina nanoparticles on crystallinity index of medium density polyethylene. For this purpose PE/Al2O3 nano-composite was prepared by dry high energy ball milling from polyethylene and Alumina nanoparticles. The materials were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The results show that during mechanical milling of PE/Al2O3 powders, the morphology and structure of the particles undergo continuous changes. Plastic deformation, chain scissions of materials are dominant mechanism which influence the characteristics of milled powders. The results show that the addition of nano-scaled alumina particles accelerated milling process of polyethylene powder. In other word, the small hard particles may act as small milling agent. Therefore, the fracture process in ball milling of polyethylene nanocomposite powders is started earlier. Another parameter that influences the ball milling process of nanocomposite powder and degree of crystallinity is the volume fraction of the reinforcement. With increasing the volume fraction of alumina particles, crystallinity percent decreases. During the early stage of milling the degree of crystallinity decreases rapidly and slows down afterwards

Keywords