Electrical, morphological, thermal and mechanical properties of low density polyethylene/zinc oxide nanocomposites prepared by melt mixing method

摘要

Inthisstudy,lowdensitypolyethylene/zincoxide(LDPE/ZnO)nanocompositeswerepreparedatdifferentconcentrationsofZnOnanoparticles,rangedfrom0to36wt%,bymeltmixingmethodusingtwin-screwextruderinordertoinvestigatetheeffectofpresenceandconcentrationchangeofnano-sizedZnOparticlesontheimpedancespectraofLDPEandalsoonmechanical,thermalandmorphologicalproperties.Then,nanocompositefilmswith170micronthicknesswereobtainedfromthegranulatednanocompositesbytwo-rollmillsandhotpressing,respectively.ElectricalpropertiesofpureLDPEandLDPE/ZnOnanocompositefilmswerestudiedbyimpedancemeasurementsoveratemperaturerangeof298ndash;400Kandinthefrequencyrangefrom50Hzto10MHz.Theroomtemperatureconductivityevaluatedfromthestraight-linefitinmeasuredI-Vplotandwasfoundtobe1.3x10-5Scm-1and4.7x10-3Scm-1forpureand18%ZnOfilledfilm,respectively.TheresultsofimpedanceanalysisshowedthattheinclusionofZnOparticlesimprovedthedielectricpropertiesofthesamples.Itwasalsoobservedthatlosstangentincreasedasthefrequencyincreasedandreachedamaximumandthereafterdecreased.ThethermaldegradationtemperaturesoftheLDPEshowedanincreasewithpresenceandincreasingcontentoftheZnOinLDPE.ItwasalsodeterminedthatthetensilestrengthofthepureLDPEraisedfrom8.01MPato8.60MPawiththeadditionofZnOnanoparticlesbutonthecontrary,theelongation(%)ofnanocompositesdecreasedapparentlyfrom1.63to0.16.