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Conductivepolymercomposites(CPCs)consistedofconductivefillerssuchascarbonblack(CB),carbonnanotubes,graphene,etc.andpolymermatrix[l],haveattractedmanyresearchersduetotheirpopularapplications,suchaselectromagneticinterferenceshielding,antistaticmaterials,shapememorymaterials,andsensors,etc.ForCPCs,thepercolationbehavior,i.e.,theinsulator-conductortransitionphenomenon,hasreceivedgreatattention.Generally,alowpercolationthresholdofaCPCleadstogoodprocessabilityandalowcost;uptonow9manyeffortshasbeendonetolowerthepercolationthresholdofCPCbymanipulatingthedistributionofconductivefillers.Amongthem,thesegregatedstructuremethod,forwhich,polymerregionsareutilizedtocreateanexcludedvolumetoenforcetheconductivefillerstoformconductivenetworksonthesurfaceofmicron-sizedpolymerparticles,hasbeenstudiedintensivelyc2].However,polymermatricesusedintheliteraturealwayshaveveryhighmeltviscosity,resultinginpooradhesionbetweenthefillerscoatedpolymerparticles;orthepolymermatricesareappliedintheformoflatex,forthisapproach,complexprocessingproceduresarealwaysinvolved.Inourwork,CB/polypropylene(PP)CPCwithasegregatedstructurewasprepared.PP,ageneralpolymerofarelativelylowermeltviscosity,wasmadeintopowderswithasizedistributionofabout10-50ymbyadissolving-smashingmethod.TheCPCwasthenpreparedbythehotcompressingmethod.Morphologystudyindicatesthataninterestingsegregatedstructureisachieved.Alowerpercolationthreshold,1.58vol%oftheCPC,whereasca7.05vol%forthecommonCB/PP,isobtained.Thatis,aconsiderablereductionofpercolationthresholdhasbeenrealized.Liquidsensingbehaviorswerealsostudiedprimitively.ItisfoundthisCPCshowsmuchhigherresponsivitythanthatofthecommonCB/PP. |
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