Photonic crystals in biology - NanoTR-VI

PPPPPP andPE.Poster Session, Thursday, June 17Theme F686 - N1123Preparation and SEM Characterization of Nanocomposites Based on HDPE and Graphite Powder12223445M. SarkanatP P, UI. H. TavmanUP P*, K. SeverP P, A. TurgutP P, Y. SekiP P, P ErbayP P, F.GünerP Pand I.Özdemir P2*1PMechanical Engineering Dept., Ege University, 35100 Bornova Izmir, TurkeyPMechanical Engineering Dept., Dokuz Eylul Univ., 35100 Bornova Izmir, Turkey3PTDepartment of Chemistry, Dokuz Eylül University, Buca, 35160 zmir, TurkeyPPetkim Petrokimya Holding A.., 35801 Aliaa-zmirPFaculty of Engineering, Bartin University, Bartin, Turkey54Abstract-Polymers which are in general insulating materials, may be made electrically and thermally conductive by the additionof conductive fillers such as graphite, carbon black, metal and metal oxide powders or fibers. In this study the conductive fillersused were nanosized graphite particles, the base material was high density polyethylene (HDPE). Nanocomposites containing upto 30 weight % of filler material were prepared by mixing them in a Brabender Plasticorder. SEM investigations of thecomposites prepared have been performed.Heat buildup in electronic components, lighting,transformer housings, and other devices that produceunwanted heat can limit service life and reduce operatingefficiency. Traditionally, metals which are good thermalconductor, has been used for thermal managementequipment such as heat sinks and heat exchangers. Butmetal parts are heavy and costly to produce. In recentyears, they are being replaced by injection molded orextruded heat-conducting plastic compounds that providelightweight cooling solutions. Advantages include designflexibility, parts consolidation, corrosion and chemicalresistance, reduction of secondary finishing operations,and the processing benefits of plastics. Polymers which ingeneral have low thermal conductivities (0.1-0.5 W/m.K)are made conductive by compounding conductive fillerssuch as graphite fibers and ceramic particles. Somethermally conductive plastics may offer up to 500 times (to100 W/mK) the conductivity of base polymers. Thesematerials can be used to tailor the thermal conductivity toindividual applications, providing the ability to dissipateheat precisely and efficiently.Various fillers, including metallic powders, are used toproduce thermally conductive polymers. Graphite powdersor fibers are frequently used especially for an improvementof electrical conductivity, antistatic properties as well asthermal conductivity of plastics, [1], [2]. The recentadvancement of nano-scale compounding techniqueenables the preparation of highly electrically conductivepolymeric nanocomposites with low loading of conductivefillers. Nanocomposites may offer enhanced physicalfeatures such as increased stiffness, strength, barrierproperties and heat resistance, without loss of impactstrength in a very broad range of common synthetic ornatural polymers. In this study the conductive filler wasgraphite with an average particle size of 400 nm and purityof 99.9%, the matrix material was high density3polyethylene (HDPE) with a density of 0.968 g/ cmP amelt index of 5.8 g/10 min, supplied by Petkim A..-zmir. Nanocomposites containing up to 30 weight % ofgraphite powder filler material were prepared by mixingthem in a Brabender Plasticorder at 180°C for 15 minutes.The mixing chamber of the Brabender apparatus was thenopened and the resulting mixture is taken out, then afterpassing through the rollers the mixture was solidified. Theresultant mixture in then put in a compression molding dieand compressed in a compression molding press at 180°C,under 40 kP pressure for five minutes to obtain samples inthe form of sheets of 1mm in thickness.SEM micrographs of graphite–HDPE composites areshown in Figure 1. It can be seen that the graphite powderare dispersed uniformly in the matrix as seen in figure 1.abcFigure 1. SEM micrographs of Graphite reinforced HDPEcomposites a) %4 by weight Graphite reinforced HDPE, b) %10by weight Graphite reinforced HDPE, c) %20 by weight Graphitereinforced HDPEThis research was supported by the Scientific Support ofthe bilateral Project No. 107M227 of TUBITAK and SASand partly by the project VEGA No. 2/0063/09.* corresponding author: HTismail.tavman@deu.edu.trT[1] Krupa,I., Chodák,I., 200, Physical Properties of thermoplastic/graphite composites, Eur. Polym. J., 37(11) 2159-2168.[2] Krupa,I., Novak,I., Chodák,I., 2004, HTElectrically andthermally conductive polyethylene/graphite composites and theirmechanical propertiesTH, Synthetic Metals, 145, 245-252.6th Nanoscience and Nanotechnology Conference, zmir, 2010 739