碳纤维增强复合材料

RESEARCHANDTREATMENTOFTHESURFACEOFCARBONFIBERINCARBONFIBERREINFORCEDCOMPOSITEScontentsPART01PART02PART03PART04PART05IntroductionCFinterfaceArticleoneArticletwoConclusions01PARTONEIntroduction01CARBONFIBERWhatisCarbonFiber?Carbonfiberisafibrouscarboncompoundthatcarbonizedbyhightemperature(1500℃)inaninertatmosphereofanorganicorlowmolecularhydrocarbongas.Thecarboncontentofthecompoundismorethan90%02CFRCWhatisCarbonfiberreinforcedcomposites?CFRCisakindofstructuralmaterialmadeofcarbonfiberwithresin,metalorceramics.Excellenttensilestrength,highstiffness,lightweightandgreatthermalresistancemakecarbonfiberreinforcedcompositesanidealstructuralmaterial.02CFRCINTERFACR:Interfaceisanintermediatephasebetweenthereinforcingphaseandthematrixphase,whichisthebridgebetweenthereinforcingphaseandthematrix,aswellasthetransmitterofstressandotherinformation.Thepropertiesofcarbonfibercompositesaredeterminedbythreemaincomponents:fiber,matrixandinterfacelayer.02PARTTWOCFinterface01INTERFACEThepropertyofCFcompositesmainlydependsonthequalityoftheinterfacebetweenthematrixandthereinforcement,whichdeterminedthewayoftheloadstransferfromthematrixtothecarbonfiber.Theimprovementoftheinterfacialadhesionstrengthbetweenthecarbonfiberandpolymermatrixisakeyfactortoimprovemechanicsperformanceofcompositematerials.02CHALLENGEOFTHEINTERFACECompositeinterfacephaseThesurfaceofcarbonfiberonlycontainselementsofC,HandO.Hydroxylandcarbonylgrouponcarbonfiberwithoutsurfacetreatmentonlyaccountforabout16.5%Therearejusttoolittleamountofpolargroupsonthesurfacewhichmakesitchallengingtocreatthebondingbetweencarbonfiberandthematrixresin.03METHODSTOENHANCETHEADHESIONFirst,preventtheformationofweakinterfacelayer.①theimpuritiesattachedtothemoldreleaseagent;②theagingoftheinterfacelayerformedwhentheoxidelayer,hydratelayer;③thesubstrateisnotfullyinfiltratedandboundbytheairlayer;…….HowtoincreasetheadhesionbetweenCFandresin?03METHODSTOENHANCETHEADHESIONSecond,thesurfacemorphologyissuitableforbonding.Theincreaseofsurfaceroughnessisbeneficialtothemechanicalfittingofcarbonfiberandmatrixresin,andtoenhancetheeffectofanchoring.Third,improvetheaffinityofresinandreinforcement.Theintroductionofpolarorreactivefunctionalgroups,andtheroleoftheintermediatelayerwithresin,suchas-COOH,-NH2,-OH.03METHODSTOENHANCETHEADHESIONsurfacetreatmentoxidationNon-oxidationVaporphaseoxidationLiquidphaseoxidationCatalyticoxidationVapordepositionmethodElectropolymerizationWhiskergrowthmethodPlasmamethod03PARTTHREEArticleone01GRAFTINGGraftingofmicro-moleculesorpolymersontothecarbonfibersurfacecanyieldacontrolled,orderedandactivestructure,whichhascanbeaneffectivemodificationmethod.D400,asatraditionalcross-linkerofepoxy,containstwoactiveprimaryaminegroupslocatedonsecondarycarbonatomsateachendofanaliphaticpolyetherchain.Andflexiblepolyetherchaincontributestostresstransferbetweencarbonfiberandepoxy.02PROCESSES增强因子重复性CFHNO3（80℃、4h）ACFHATUwasusedascondensingagentWasheddriedinavacuumfurnaceACF/D400carbonfiberreinforcedepoxycompositeswashedseveraltimes，driedundervacuumD400（90℃、4h）epoxy03RESULTSANDDISCUSSIONThefollowingdepictsthesurfacemorphologiesandroughnessofthecarbonfibers.SurfaceofuntreatedCFissmooth，afteracidtreatmentthesmoothsurfaceofcarbonfiberchangestobecoarseduetotheabsorptionofD400ontocarbonfibersurface.03RESULTSANDDISCUSSIONThewettabilityofcarbonfiberisinvestigatedusingadvancingdynamiccontactangletest.AfterD400graftingtreatment,thecontactanglesdecrease,whilethesurfaceenergyofcarbonfiberincreases.ThewettabilityofcarbonfiberwasincreasedandthechangeofthefibersurfacefreeenergyconfirmsthesuccessfuldepositionofD400oncarbonfibersurface.03RESULTSANDDISCUSSIONIFSSwasadoptedtoquantifytheinterfacialpropertybetweencarbonfiberandepoxy.F----maximumloadrecordedd----carbonfiberdiameterl------embeddedlengthAfteradsorptionofD400,theIFSSofCF/D400compositeincreasesto55.8MPawhichisattributedtoimprovementofsurfaceenergy.D400,whichcannotonlyreactwiththereactivegroupsonthecarbonfibersurface,butalsoincreaseresincompatibilityandreactwiththematrixsystem.D400moleculeshaveexactlyandcompletelycoveredthewholesurfaceofcarbonfibersat2*10-4mol/Lconcentration.03RESULTSANDDISCUSSIONThefollowingdepictsthesurfacemorphologyofcarbonfibersafterdebondingfromtheepoxymatrixBeforegrafting（Figa）,thedebondingbetweencarbonfiberandepoxyisinterfacialfailure.AfteradsorbedD400,moreepoxydebrisadhereonthecarbonfiberafterdebonding,duetothestrongcovalentbondsformedbetweenaminoandcarboxylgroups.AsD400concentrationgoesup,thereismoreremainingepoxyresin.03RESULTSANDDISCUSSIONItcanbeseenthatthetensilestrengthofallD400treatedcarbonfibersarealittlehigherthanthatoftheuntreatedCF(4.73GPa).ThetensilestrengthofD400graftedcarbonfiberincreasedslightlywiththeincreaseofconcentrationTheresultsimplythatD400graftingcannotonlymakeupthetensilestrengthlossesduetotheetchingeffectduringtheacidtreatment,butalsomildlyenhancetensilestrengthofcarbonfiber.Tensilestrengthofsinglefiberwasmeasuredbytensiletest.04PARTFOURArticletwo01IntroductionAtwo-stepmethodforhighefficientandcontinuousca