Photonic crystals in biology - NanoTR-VI

PPPPoster Session, Thursday, June 17Theme F686 - N1123Electrical Behaviours of Flame Retardant Huntite and Hydromagnesite Reinforced PolymerComposites for Cable Applications1,21,2UHüsnügül Ylmaz AtayUPP*, Erdal ÇelikPPDepartment of Metallurgical and Materials Engineering, Dokuz Eylul University, 35160 Izmir, TurkeyPCenter for Fabrication and Applications of Electronic Materials, Dokuz Eylul University, 35160 Izmir, Turkey21Abstract - As huntite and hydromagnesite mineral undergoes an endothermic decomposition with water and carbon dioxide release, it hasbeen studied as flame retardant filler for polymers in potential electrical applications. In this study, the electrical properties of flame retardanthuntite and hydromagnesite mineral reinforced polymeric composites were investigated. Phase and microstructural analysis of huntite andhydromagnesite powders were undertaken using XRD and SEM-EDS preceeding the fabrication of the composite materials. The mineralswith different particle size and content were subsequently added to ethylene vinyl acetate copolymer to produce composite materials. Afterthe fabrication of composites, their electrical properties such as conductivity, dielectric constant, specific resistance, impedance, capacitanceand dissipation factor were investigated as a function of particle size and loading level. It was concluded that conductivity increased withdecreasing particle size to nanoscale.Due to their low weight and ease of processing, the useof polymers is arised by their remarkable combination ofproperties in our daily life. Even though to be used in somany areas and show great facilities, polymers are alsoknown for their relatively high flammability. Beside, mostof them are accompanied by corrosive or toxic gases andsmoke which are produced while the combustion iscontinuing [1]. So that, it is rising as an important issue toextent polymers’ usage for obtaining their fire resistingproperty for the applications [2]. Hence some ancillarymaterials are used to make polimers fire resistant. They areadded into the compound whose application propertiesbecame closely related to the physical properties of theadditive itself. Huntite/hydromagnesite is a halojen freeinorganic mineral that can be used as a flame retardantadditive to the flammable polymeric materials. Itseffectiveness comes from the fact that it decomposesendothermically and consumes a large amount of heat,while also liberating water, which can dilute any volatilesand thus decrease the possibility of fire (Equations 1 and2) [3]. Decomposition begins at somewhat highertemperature, near 400°C, and consumes 1244 J/g [4].MgR4R(COR3R)R3R(OH)R2R.3HR2RO 4MgO + 3COR2R+4HR2RO (1)MgR3RCa(COR3R)R4R 3MgO + CaO + 4COR2R (2)In the present work, a series of composites wereprepared using an ethlylene vinyl acetate copolymermatrix and different concentrations ofhuntite/hydromagnesite mineral to ethylene vinyl acetatecopolymer to evaluate the electrical properties. In thissense, properties of complex conductivity, impedance,capacitance, dissipatation factor, dielectric constant andspecific resistance measurements were performed tohuntite hydromagnesite reinforced plasticcompositesamples.. Only conductivity test results is shown here (Figure 1).The result shows that decreasing the size to nano scalemakes the polymer composite more conductive. On theother hand, in spite of the fact that it seems to be changingthe conductivity related with the loading level, it can beexpressed that increasing filler amaount increased thepolymer’s conductivity. The increase in conductivity withthe increasing of the filler amount mainly stems from theestablishing of conducting networks in the polymer matrix[5]. In addition, we have a good aggrement with theliterature [6] that finer particles may support thismechanism as the ionic conductivity of the polymercomposite increased. In toher words, for both size effectand the loading level effect tests, it can be seen thatfrequency assists helps to increase conductivity of thecomposites. The other electrical properties such asdielectric constant, specific resistance, impedance,capacitance and dissipation factor were improved withchanging particle size and content.Complex Conductivity (S/cm)(a)0,350,300,250,200,150,100,050,00-0,0510 μm1 μm0.1 μm0,0 2,0x10 6 4,0x10 6 6,0x10 6 8,0x10 6 1,0x10 7Frequency (Hz)Complex Conductivity (S/cm)0,320,300,280,260,240,220,200,180,160,140,120,100,080,060,040,020,00-0,0249%55%61%64%67%69%0,0 2,0x10 6 4,0x10 6 6,0x10 6 8,0x10 6 1,0x10 7(b)Frequency (Hz)Figure 1. Conductivity of huntite/hydromagnesite reinforcedplastic composite materials as a function of frequency accordingto (a) particle sizes and (b) contents of reinforced powderThe authors would like to acknowledge to Likya MinelcoMadencilik Sti. and Minelco Specialities Limited.*Corresponding Author: HThgulyilmaz@gmail.comTH[1] O’Driscoll, Mike. (1994). Industrial Minerals December.[2] F. Laoutid, L. Bonnaud, M. Alexandre, J.-M. Lopez-Cuesta,Ph. Dubois (2008). Materials Science and Engineering R[3] Ahmed Basfar, and H. J. (2009) Journal of Fire Sciences.[4] Haurie, L., at al. (2006). Polymer Degr. And Stability 91 (5)989-994.[5] Guohua Chen at al (2007).Mat. Chem. and Phy. 104 240–243[6] Zhaoyin Wena at al. (2003) Solid State Ionics 160 141– 1486th Nanoscience and Nanotechnology Conference, zmir, 2010 715