Abstract—In this study, Multiwall Carbon Nanotubes (MWCNT) reinforced High Density Polyethylene (HDPE) materials were used. Mechanical properties of the samples reinforced with Carbon Nanotubes at weight ratios of 1%, 3% and 5% were investigated. Reinforced samples were compared to samples produced with pure High density Polyethylene. Samples were produced by plastic injection method. The samples were then subjected to experiments and impact resistance values were measured in accordance with ASTM D6110 standards. Also Thermogravimetric Analyses (TGA) was performed for and Multi-Wall Carbon Nanotubes within the High Density Polyethylene. At the end of the study, it was observed that impact resistance decreased with increasing carbon nanotube reinforcement amount. Impact resistance of samples produced by means of plastic injection was decreased by 35% comparing with samples produced from pure HDPE. These results were explained with the fact that structures of composite materials were transformed to a tougher and fragile phase. In the TGA investigations, it was seen that mass loss breakdown temperature and melting point temperature increased by MCWNT ratio in the composite samples. Index Terms—Carbon nanotubes, high density polyethylene, nanocomposites, impact, TGA. I. INTRODUCTION Since the documented discovery of CNTs in 1991 by Iijima [1] and the realization of their unique physical properties, including mechanical, thermal, and electrical, many investigators have endeavored to fabricate advanced CNT composite materials that exhibit one or more of these properties [2]-[4]. For example, as conductive filler in polymers, CNTs are quite effective compared to traditional carbon black microparticles, primarily due to their large aspect ratios [5]. Similarly, CNTs possess one of the highest thermal conductivities known [6], which suggests their use in composites for thermal management [2]. The main focus of this paper, however, will be on the use of CNTs as discontinuous reinforcement for polymer matrices. The CNT can be thought of as the ultimate carbon fiber with break strengths reported as high as 200 GPa, and elastic module in the 1TPa range [7], [8]. Manuscript received July 28, 2015; revised October 8, 2015. Murat Mirik is with Cumhuriyet University, Sivas Vocational School, Sivas, Turkey (e-mail: mmirik@cumhuriyet.edu.tr). Şerafettin Ekinci is with Selcuk University, Technology Faculty, Mechanical Engineering Department, Konya, Turkey (e-mail: sekinci@selcuk.edu.tr). Mustafa Taşyürek is with Selcuk University, Technology Faculty, Metallurgical and Material Engineering Department, Konya, Turkey (e-mail: mtasyurek@selcuk.edu.tr). CNTs are graphitic sheets rolled into seamless tubes (i.e. arrangements of carbon hexagons into tube like fullerenes) having a diameter ranging from about a nanometer to tens of nanometers with lengths up to centimeters. Both theoretical and experimental studies have shown CNTs to have extremely high tensile module (>1 TPa for single walled carbon nanotubes, SWCNTs) and tensile strengths of the order of 500 GPa [9], [10]. Carbon nanotubes are thermally stable up to over 2400˚C in vacuum, have a thermal conductivity along their principal axes about double than that of diamond and electric-current-carrying capacity up to 1000 times higher than copper wire. Due to their extraordinary mechanical, electrical and optical properties together with their low density (1.3-2.4 g/cm 3 ), CNTs have attracted great attention in recent years in the field of composites materials. As the structure and properties of the CNTs have been understood, there is a pressing need to transfer their outstanding properties from nano to micro/macro-scales. One essential step towards this goal is their processing, which often involves dispersing them in a polymeric matrix to form complex materials such as polymer-CNTs nanocomposites. These composites represent the first realized major commercial application of CNTs [11]. The addition of nanostructured materials, such as CNTs, to polymers offers a viable means of altering the mechanical [12], [13], thermal [3]-[14] and electrical [15], [16] properties of polymer-based composite materials. The resulting properties include tensile strengths of 100–600 GPa, a density of around 1.3 g/cm 3 , elastic module of 200–5000 GPa and fracture strains of 10–30% [17], [18]. CNTs have desirable mechanical properties that make them particularly attractive for strengthening polymers [19]. II. MATERIALS AND METHODS This section with High Density Polyethylene multiwalled carbon nanotube formed into a composite material which comprises the experiments. Properties of carbon nanotube are given at Table I, and properties of thermoplastic matrix are given at Table II. The samples used in this study, is available from Fibermax Composites Multi-Walled Carbon Nanotubes with PETKİM Petrochemical Holding CO. is located in Izmir Aliaga. Quality Control and Technical Services Manager facilities are connected to the work done, again obtained from PETKİM F00556 combined with High Density Polyethylene was granulated. Impact test samples were produced within the required Charpy Impact Resistances of Carbon Nanotubes Reinforced High Density Polyethylene Nanocomposite Materials Murat Mirik, Şerafettin Ekinci, and Mustafa Taşyürek International Journal of Materials, Mechanics and Manufacturing, Vol. 4, No. 4, November 2016 247 doi: 10.18178/ijmmm.2016.4.4.265