ASTM-D7028-2007用DMA测试Tg

Designation:D7028–07´1StandardTestMethodforGlassTransitionTemperature(DMATg)ofPolymerMatrixCompositesbyDynamicMechanicalAnalysis(DMA)1ThisstandardisissuedunderthefixeddesignationD7028;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.´1NOTE—ReferencetoaresearchreportwasaddedandfigurescorrectedinAugust2008.1.Scope1.1Thistestmethodcoverstheprocedureforthedetermi-nationofthedryorwet(moistureconditioned)glasstransitiontemperature(Tg)ofpolymermatrixcompositescontaininghigh-modulus,20GPa(33106psi),fibersusingadynamicmechanicalanalyzer(DMA)underflexuraloscillationmode,whichisaspecificsubsetoftheDynamicMechanicalAnalysis(DMA)method.1.2Theglasstransitiontemperatureisdependentuponthephysicalpropertymeasured,thetypeofmeasuringapparatusandtheexperimentalparametersused.Theglasstransitiontemperaturedeterminedbythistestmethod(referredtoas“DMATg”)maynotbethesameasthatreportedbyothermeasurementtechniquesonthesametestspecimen.1.3Thistestmethodisprimarilyintendedforpolymermatrixcompositesreinforcedbycontinuous,oriented,high-modulusfibers.Othermaterials,suchasneatresin,mayrequirenon-standarddeviationsfromthistestmethodtoachievemeaningfulresults.1.4ThevaluesstatedinSIunitsarestandard.Thevaluesgiveninparenthesesarenon-standardmathematicalconver-sionstocommonunitsthatareprovidedforinformationonly.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D3878TerminologyforCompositeMaterialsD4065PracticeforPlastics:DynamicMechanicalProper-ties:DeterminationandReportofProceduresD4092TerminologyforPlastics:DynamicMechanicalPropertiesD5229/D5229MTestMethodforMoistureAbsorptionPropertiesandEquilibriumConditioningofPolymerMa-trixCompositeMaterialsE177PracticeforUseoftheTermsPrecisionandBiasinASTMTestMethodsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethodE1309GuideforIdentificationofFiber-ReinforcedPolymer-MatrixCompositeMaterialsinDatabasesE1434GuideforRecordingMechanicalTestDataofFiber-ReinforcedCompositeMaterialsinDatabasesE1471GuideforIdentificationofFibers,Fillers,andCoreMaterialsinComputerizedMaterialPropertyDatabasesE1640TestMethodforAssignmentoftheGlassTransitionTemperatureByDynamicMechanicalAnalysisE1867TestMethodforTemperatureCalibrationofDy-namicMechanicalAnalyzers3.Terminology3.1Definitions—TerminologyD3878definestermsrelatingtopolymermatrixcomposites.TerminologyD4092definestermsrelatingtodynamicmechanicalpropertymeasurementsonpolymericmaterials.3.2Symbols:E’=storagemodulusE”=lossmodulustand=E”/E’=tangentdeltaDMATg=glasstransitiontemperaturedefinedfromdy-namicmechanicalanalysismeasurementL=lengthofspecimenW=widthofspecimenT=thicknessofspecimenTt=peaktemperaturefromtangentdeltacurve4.SummaryofTestMethod4.1AflatrectangularstripoflaminateisplacedintheDMAequipmentandoscillatedatanominalfrequencyof1Hz.Thespecimenisheatedatarateof5°C/min(9°F/min).Thesame1ThistestmethodisunderthejurisdictionofASTMCommitteeD30onCompositeMaterialsandisthedirectresponsibilityofSubcommitteeD30.04onLaminaandLaminateTestMethods.CurrenteditionapprovedDec.15,2007.PublishedJanuary2008.2ForreferencedASTMstandards,visittheASTMwebsite,@astm.org.ForAnnualBookofASTMStandardsvolumeinformation,refertothestandard’sDocumentSummarypageontheASTMwebsite.1Copyright©ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959,UnitedStates.loadingfrequencyandheatingrateisusedforbothdryandwetspecimens(moistureconditioned)toallowforcomparison.Thetemperatureatwhichasignificantdropinstoragemodulus(E’)beginsisassignedastheglasstransitiontemperature(DMATg).Thepeaktemperatureofthetangentdeltacurve(Tt)isidentifiedalongwithDMATgforcomparisonpurposes.5.SignificanceandUse5.1ThistestmethodisdesignedtodeterminetheglasstransitiontemperatureofcontinuousfiberreinforcedpolymercompositesusingtheDMAmethod.TheDMATgvalueisfrequentlyusedtoindicatetheupperusetemperatureofcompositematerials,aswellasforqualitycontrolofcompositematerials.6.Interferences6.1ThestandardtestingmachineshallbeoftheDynamicMechanicalAnalysis(DMA)typeofinstrumentthatoperateswithforcedoscillationandappliesaflexuralloadingmode(eitherthree-pointbendordualcantilever)tothetestspecimen.RefertoPracticeD4065forasummaryofvariousotherDMApractices.Otherloadingmodes(suchastensile,torsionorshear)mayproducedifferenttestresults.Ifanotherequipmenttypeorloadingmodeisusedthenon-standardapproachshallbedescribedinthereportandthetestresultrecordedasnon-standard.6.2Afixedfrequencyof1Hzisstandardinthistestmethod.Ingeneral,foragivenmaterial,ahighertestingfrequencyproducesahigherDMATgvaluethanthisstandard,whileuseoftheresonancemodewillyieldadiff