碳纤维增强复合材料

RESEARCHANDTREATMENTOFTHESURFACEOFCARBONFIBERINCARBONFIBERREINFORCEDCOMPOSITESPART01PART02PART03PART04PART05IntroductionCFinterfaceArticleone

ArticletwoConclusions01PARTONEIntroduction01CarbonFiber

What

isCarbonFiber?Carbonfiberisafibrouscarboncompoundthatcarbonizedbyhightemperature(1500℃)inaninertatmosphereofanorganicorlowmolecularhydrocarbongas.Thecarboncontentofthecompoundismorethan90%02CFRCWhat

isCarbonfiberreinforcedcomposites

?CFRCisakindofstructuralmaterialmadeofcarbonfiberwithresin,metalorceramics.Excellenttensilestrength,highstiffness,lightweightandgreatthermalresistancemakecarbonfiberreinforcedcompositesanidealstructuralmaterial.02CFRCINTERFACR:Interface

isanintermediatephasebetweenthereinforcingphaseandthematrixphase,whichisthebridgebetweenthereinforcingphaseandthematrix,aswellasthetransmitterofstressandotherinformation.Thepropertiesofcarbonfibercompositesaredeterminedbythreemaincomponents:fiber,matrixandinterfacelayer.02PARTTWOCFinterface01interfaceThepropertyofCFcompositesmainlydependsonthequalityoftheinterfacebetweenthematrixandthereinforcement,whichdeterminedthewayoftheloadstransferfromthematrixtothecarbonfiber.Theimprovementoftheinterfacialadhesionstrengthbetweenthecarbonfiberandpolymermatrixisakeyfactortoimprovemechanicsperformanceofcompositematerials.02ChallengeoftheinterfaceCompositeinterfacephaseThesurfaceofcarbonfiberonlycontainselementsofC,HandO.Hydroxylandcarbonylgrouponcarbonfiberwithoutsurfacetreatmentonlyaccountforabout16.5%

Therearejusttoolittleamountofpolargroups

onthesurfacewhichmakesitchallengingtocreatthebondingbetweencarbonfiberandthematrixresin.03MethodstoenhancetheadhesionFirst,preventtheformationofweakinterfacelayer.①theimpuritiesattachedtothemoldreleaseagent;②theagingoftheinterfacelayerformedwhentheoxidelayer,hydratelayer;③thesubstrateisnotfullyinfiltratedandboundbytheairlayer;…….HowtoincreasetheadhesionbetweenCFandresin?03MethodstoenhancetheadhesionSecond,thesurfacemorphologyissuitableforbonding.Theincreaseofsurfaceroughnessisbeneficialtothemechanicalfittingofcarbonfiberandmatrixresin,andtoenhancetheeffectofanchoring.Third,improvetheaffinityofresinandreinforcement.Theintroductionofpolarorreactivefunctionalgroups,andtheroleoftheintermediatelayerwithresin,suchas-COOH,-NH2,-OH.03MethodstoenhancetheadhesionsurfacetreatmentoxidationNon-oxidationVaporphaseoxidationLiquidphaseoxidationCatalytic

oxidationVapordepositionmethodElectropolymerizationWhiskergrowthmethodPlasmamethod03PARTTHREEArticleone01Grafting

Graftingofmicro-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.D400

moleculeshaveexactlyandcompletelycoveredthewholesurfaceofcarbonfibersat2*10-4

mol/Lconcentration.

03ResultsanddiscussionThefollowingdepictsthesurfacemorphologyofcarbonfibersafterdebondingfromtheepoxymatrixBeforegrafting（Figa）,thedebondingbetweencarbonfiberandepoxyisinterfacialfailure.AfteradsorbedD400,moreepoxydebrisadhereonthecarbonfiberafterdebonding,duetothestrongcovalentbondsformedbetweenaminoandcarboxylgroups.AsD400

concentrationgoesup,thereismoreremainingepoxyresin.03ResultsanddiscussionItcanbeseenthatthetensilestrengthofallD400

treatedcarbonfibersarealittlehigherthanthatoftheuntreatedCF(4.73GPa).ThetensilestrengthofD400

graftedcarbonfiberincreasedslightlywiththeincreaseofconcentrationTheresultsimplythatD400graftingcannotonlymakeupthetensilestrengthlossesduetotheetchingeffectduringtheacidtreatment,butalsomildlyenhancetensilestrengthofcarbonfiber.Tensilestrengthofsinglefiberwasmeasuredbytensiletest.04PARTFOURArticletwo01IntroductionAtwo-stepmethodforhighefficientandcontinuouscarbonfibertreatmentwithenhancedfiberstrengthandinterfacialadhesionAlthoughnumeroussurfacetreatmentmethodshavebeenproposedtoimprovethesmoothandinertsurfaceofcarbonfibers,mostofthemareusuallyaccompaniedbythedamageoffiberstrength01IntroductionAtwo-stepmethodplasmatreatingPyCcoatingSTEPONESTEPTWO01IntroductionCarboncoatingwhichhassimilarchemicalcompositionandstructurewithcarbonfibersisconsideredasanotherpotentialsurfaceprotectivematerialforcarbonfiberscarboncoatingpyrolyticcarbon(PYC)Thealkaneorcarbideweredepositedonthesurfaceofcarbonfiberafterpyrolysistoformfilmwithahightemperature01IntroductionPyCfromethanolpyrolyticcarbon(PyC)usingethanolprecursorhasattractedmuchattentionbecausethehydroxylgroupinethanolcanmakethePyCstructuredenseandcontrollable.PyCwiththethicknessofseveraltensofnanometerscouldeffectivelyhealtheflawsonthecarbonfibers,andincreasetheirtensilestrengthPyC

for

carbon

fiberSurfacePyCcoating01IntroductionDuetoweakboundarylayerandthe

pollutantsoncarbonfibersurface,thebindingstrengthbetweenPyCandCFisweakwhichusuallyresultsindebondingbetweenthesetwophaseswhenthecompositesareunderloading.ChallengeofPyCPlasmatechnologyWeakboundarylayerandthepollutantsreactswiththeplasmaandwereetchedtoformavolatilesubstance.pollutantsplasmasurface01IntroductionAtwo-stepmethodplasmatreatingPyCcoatingRemovetheweakboundarylayerandthepollutantsonthesurfaceoftheCFEnhancetheroughnessandincreasetheadhesionbetween

theCFandmatrix02measurement①Morphologies

SEM②Thesurfaceroughness,thicknessandmodulusofPyCcoatingAFM③surfacecompositionand

surfaceenergyXPS④mechanicalproperty

universal

testing

machine

(AtomicForceMicroscope)(X-rayphotoelectronspectroscopy)03Results-morphologiesthereareafewnarrowgroovesdistributingalongtheuntreatedfiberaxialdirection.(a)Untreatedfibers(b)plasmatreatedfibersthesurfacebecomesrougherandthegroovesbecomemoreobviousnumerousparticlesofseveralnanometerscoverthewhole

fiber(c)PyCcoatedfibers03Results-surfacecomposition

Theremovaloftheweakboundarylay,oxidesandpollutantsbyno-reactiveheliumplasmaetching.Theamountsofcarbonandnitrogenincreaseslightlyandoxygencontentdrops03Results-surfacecomposition

NitrogenthatderivesfromthepolyacrylonitrileprecursorisnotdetectedItimpliesthatthecarbonfiberistotallycoveredbyPyC03Results-surfacecomposition

theirsurfacecompositionisquitedifferentfromthoseoffiberscoveredwithPyC.Itcanbeattributedtotheoxidationandtheoxygen-containinggroupsinepoxysizing03Results-surfaceenergy

Thewettabilityofcarbonfibersinfluencestheinterfacialadhesionofthecomposites.Thehighersurfaceenergy,nomatteritspolarordispersioncomponent,canleadtobetterwettabilityofthefibersbytheresinandstrongerinterfacialadhesioninthecomposites03Results-surfaceenergy

thedispersioncomponent（γd）showsaslightincreasethepolarcomponent（γp）

ofsurfaceenergyreducesslightly.theincreasedsurfaceroughness03Results-surfaceenergy

Asthereasonoftheroughsurfaceanddifferentgraphitestructure,thesurfaceenergyofthefiberaftercoatedwithPyCincreasessignificantly,especiallyforthedispersioncomponent03Results-surfaceenergy

Forthecommercialfibers,thesurfaceenergyismuchhigherthanthatofthePyCcoatedfibers,whichisduetothenumerousoxygengroupsonfibersurface.03Results-mechanicalpropertythefiberstrengthisnotobviouslyaffectedafterplasmaetchingtheplasmaonlytakesactioninthedepthofseveralnanometers03Results-mechanicalpropertythefiberstrengthincreasesdramaticallyfrom3.02to3.43GPaandthedatadispersionisthelowestamongthefivegroupsamplesthehealingeffectoftheuniformPyContheflawsofthefibersurface.03Results-mechanicalpropertyAfterthecommercialanodicoxidationtreatment,thefiberstrengthdecreasesslightlyto2.87GPa.

03Results-mechanicalpropertyThestrengthincreasesagainto3.20GPa,whichmeanstheflawscreatedbyanodicoxidationarehealed.03Results-mechanicalpropertyILSSwasusedtoassesstheeffectofPyCcoatingontheinterfacialadhesionofthecomposites.03Results-mechanicalpropertyTheILSSofthePyCcoatedfaberincreasesfrom70.1to85.7MPa①PyCcoatingincreasethefibersurfaceroughnesswhichcouldsupplystrongmechanicalinterlocking;②Surfaceenergywhichcouldmakepolymerw