聚乙烯醇缩丁醛石墨烯纳米复合材料的制备与表征

JPolymRes(2012)19:9966DOI10.1007/s10965-012-9966-6

ORIGINALPAPER

Preparationandcharacterization

ofPolyvinylbutyral/GrapheneNanocomposite

MortazaHajian&MohammadRezaReisi&

GholamAliKoohmareh&AliRezaZanjaniJam

Received:18December2011/Accepted:16August2012/Publishedonline:27September2012#SpringerScience+BusinessMediaB.V.2012

AbstractPoly(vinylbutyral)(PVB)wassynthesizedbycondensationofpoly(vinylalcohol)(PVA)withbutyralde-hyde.NanocompositesofPVBwithgraphene(0.1to0.6wt%)werepreparedviasolutionblending.ThestructureandpropertiesofpreparedcompoundswerecharacterizedbyFT-IR,X-raydiffraction(XRD),thermalgravimetricanalysis(TGA),scanningelectronmicroscopy(SEM)andtensilestrengthtester(TST).ThepreparednanocompositesshowedconsiderablethermalandmechanicalpropertiesthanPVBandshowedgoodtoughnessandflexibility.KeywordsPoly(vinylbutyral).Graphene.Mechanicalproperties.Nanocomposite

Introduction

Grapheneisaplanarsheetofsp2-hybridizedcarbonatoms,arrangedintwodimensionallatticethathasrecentlyattractedalargeamountofattentionbecauseofitselectronicandthermalproperties[1–6].

Dispersionofgraphenenanosheetsinpolymerhostsarechallengesinthedevelopmentofhigh-performancegraphene-basednanocompositesduetothestronginterlayercohesiveenergyandsurfaceinertia[7,8].

Asimpleandpracticalapproachhasbeenreportedtosynthesizegraphene-reinforcedpoly(vinylalcohol)(PVA)compositefilmsbyincorporatinggraphiteoxideandgraphene

M.HajianM.R.Reisi(*)G.A.KoohmarehA.R.ZanjaniJam

DepartmentofChemistry,CollegeofScience,UniversityofIsfahan,Isfahan81746-73441,Iran

e-mail:chemreza2002@http://

intoPVAaqueoussolution.Theresultingnanocompositesrevealedincreasesofupto212%intensilestrengthand34%inelongationatbreakwithonly0.5wt%graphenecontent.Measurementsshowedthatthewaterabsorptionratioofthegraphene/PVAcompositesdecreasedfrom105.2to48.8%,andthebarrierpropertieswereobviouslyimproved[9].

Graphenenanosheets–poly(methylmethacrylate)(GNS–PMMA)nanocompositeswerefirstpreparedbyinsitususpensionpolymerizationandreductionofgrapheneoxideusinghydrazinehydrateandammonia.PMMAmicro-sphereswithameandiameterof2μmaremainlycovalentlylinktothesurfaceofGNS.TheobtainedGNS–PMMAcompositeshavenotonlyhighelectricalconductivitybutalsoenhancedmechanicalpropertiesandthermalstabilityatlowloadingsofgraphene.Especially,theresultingnano-compositeswereexaminedforelectrorheologicalfluids,showingthinanddensechainsofparticlesafterapplicationofanelectricfield[10].

Mechanicalpropertiesofepoxynanocompositeswithgrapheneplatelets,single-walledcarbonnanotubes,andmulti-walledcarbonnanotubeadditiveswerecomparedatananofillerweightfractionof0.1±0.002%.Themechan-icalpropertiesmeasuredweretheYoung’smodulus,ulti-matetensilestrength,fracturetoughness,fractureenergy,andthematerial’sresistancetofatiguecrackpropagation.Theresultsindicatethatgrapheneplateletssignificantlyout-performcarbonnanotubeadditives.TheYoung’smodulusofthegraphenenanocompositewas~31%greaterthanthepristineepoxyascomparedto~3%increaseforsingle-walledcarbonnanotubes.Thetensilestrengthofthebase-lineepoxywasenhancedby~40%withgrapheneplateletscomparedto~14%improvementformulti-walledcarbonnanotubes.Thefracturetoughnessofthenanocompositewithgrapheneplateletsshowed~53%increaseoverthe

Page2of7

Table1formulationforpreparationofPVB/graphenenancopositesSample

PVB(g)1.61.61.61.6

DOP(g)0.40.40.40.4

graphene(mg) 1.64.89.6

SDS(mg) 164896

Ethanol(ml) 164896

JPolymRes(2012)19:9966

ExperimentalMaterials

PVAwithMn072000gmole 1anddegreeofpolymer-ization1600andmeltingpoint230°CwaspurchasedfromAppliChemCompany,ButanalwaspurchasedfromAldrichCompany.GraphitewaspreparedfromTehranPetroleumCo.OtherchemicalswerepurchasedfromMerck.Instrumentation

FTIRspectrawererecordedonaJASCOFTIR-6300spectrometerbyusingKBrpellets.ThermogravimetricAnalysis(TGA),wererecordedonaSETARAMlabsysTGsystemconductedoverthetemperaturerangefrom25to600°Cwithaprogrammedtemperatureincre-mentof10°Cmin 1underN2atmosphere.TGsystem.Scanningelectronmicroscopy(SEM,AIS-2100Model-550-SERONTechnology)wasusedtoanalyzethemor-phologyofthematerials.X-raydiffractionswereper-formedonBrukerD8Advanceinstrument.TensiletestswereperformedusingSMT5modelofSANTAMCompany.

PVB

PVB/0.1%graphenePVB/0.3%graphenePVB/0.6%graphene

epoxycomparedto~20%improvementformulti-walledcarbonnanotubes.Thefatigueresistanceresultsalsoshowedsignificantlydifferenttrends.Whilethefatiguesup-pressionresponseofnanotube/epoxycompositesdegradesdramaticallyasthestressintensityfactoramplitudeisin-creased,thereverseeffectisseenforgraphene-basednanocomposites.

Thesuperiorityofgrapheneplateletsovercarbonnano-tubesintermsofmechanicalpropertiesenhancementmayberelatedtotheirhighspecificsurfacearea,enhancednanofiller-matrixadhesion/interlockingarisingfromtheirwrinkled(rough)surface,aswellasthetwo-dimensional(planar)geometryofgrapheneplatelets[11].

Here,newnanocompositesofPVBwithgraphenewerereported.

Scheme1ReactionofPVAandbutanalforpreparationofPVB

JPolymRes(2012)19:9966Page3of7

Fig.1FT-IRspectrumof

PVB

SynthesisSynthesisofPVB

PVBwaspreparedaccordingtothefollowingprocedure:Aoneliterthree-neckedflask,equippedwithacondenser,andmechanicalstirrer,chargedwithPVA(14g,304.82mmolOHgroup),water(140ml),aceticacid(140ml),andsodiumdodecylsulfate(SDS)(0.21g,0.73mmol).pHofthemixturewasadjustedto2.5bysulfuricacidandthetemperaturemaintainedat8–10°C.Butanal(8.12g,112.60mmol)wasaddedandthereactionmixturewasstirredfor120min.Thetemperaturewasthenraisedto70°Cfor90minanddistilledwaterwasaddedtothereactorandPVBwasprecipitated.

The

Fig.2XRDpatternsofagraphite,bgraphiteoxide,cgraphene,dpurePVBandePVB/graphenenanocomposite

Page4of7Fig.3SEMmicrographofgraphite

surface

precipitatewaswashedbysodiumhydroxidesolution(50%)topH10–11andthenrewashedwithwatertoadjustpHto8andfinally …… 此处隐藏：11304字，全部文档内容请下载后查看。喜欢就下载吧 ……