【astm標(biāo)準(zhǔn)】d 4878 - 15

1、Designation:D4878?15StardTestMethodsfPolyurethaneRawMaterials:DeterminationofViscosityofPolyols1ThisstardisissuedunderthefixeddesignationD4878thenumberimmediatelyfollowingthedesignationindicatestheyearofiginaladoptionint

2、hecaseofrevisiontheyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperepsilon()indicatesaneditialchangesincethelastrevisionreapproval.1.Scope1.1Thesetestmethods(AB)determinetheviscosityofpolyol

3、sintherangefrom10to100000mPas(cP)at25C.TestMethodAisarotationalprocedurefdeterminingdynamicviscosity.TestMethodBisageneralprocedurefkinematicviscosityoftransparentpolyols.(SeeNote1.)1.2ThevaluesstatedinSIunitsaretoberega

4、rdedasthestard.Otherequivalentunitsareprovidedbecauseofcurrentcommonusage.1.3Thisstarddoesnotpurpttoaddressallofthesafetyconcernsifanyassociatedwithitsuse.Itistheresponsibilityoftheuserofthisstardtoestablishappropriatesa

5、fetyhealthpracticesdeterminetheapplicabilityofregulatylimitationspritouse.NOTE1—TestMethodAisequivalenttoISO3219.TestMethodBisequivalenttoISO3104.2.ReferencedDocuments2.1ASTMStards:2D445TestMethodfKinematicViscosityofTra

6、nsparentOpaqueLiquids(CalculationofDynamicViscosity)D446SpecificationsOperatingInstructionsfGlassCapillaryKinematicViscometersD883TerminologyRelatingtoPlasticsE2251SpecificationfLiquidinGlassASTMThermometerswithLowHazard

7、PrecisionLiquids2.2ISOStards:3ISO3104PetroleumProducts—TransparentOpaqueLiquids—DeterminationofKinematicViscosityCalculationofDynamicViscosityISO3219Plastics—PolymersResinsintheLiquidStateofasEmulsionsDispersions—Determi

8、nationofViscosityUsingaRotationalViscometerwithDefinedShearRate3.Terminology3.1FdefinitionsoftermsusedinthesetestmethodsseeTerminologyD883.4.SignificanceUse4.1Thesetestmethodsaresuitablefresearchasqualitycontrolspecifica

9、tiontests.4.2Viscositymeasurestheresistanceofafluidtounifmlycontinuousflowwithoutturbulenceotherfces.5.Sampling5.1Polyesterpolyetherpolyolscontainmoleculescoveringanappreciablerangeofmolecularweights.Thesecanfractionated

10、uringsolidification.Unlessthematerialisafinelygroundsoliditisnecessarytomelt(usingnohighertemperaturethannecessary)mixthepolyolwellbeferemovingasamplefanalysis.Manypolyolsarehygroscopiccareshouldbetakentoprovideminimumex

11、posuretoatmosphericmoistureduringthesampling.TESTMETHODA—ROTATIONALVISCOSITY6.SummaryofTestMethod6.1Theviscosityismeasuredbydeterminingthetqueonaspindlerotatingatconstantspeedintheliquidsampleat2560.1C.Generationofcompar

12、ativedatausingthismethodrequiresagreementonthespeedspindletemperaturetimeofrotationtquerangeoftheinstrumentused.7.Apparatus7.1ConstantTemperatureBathcapableofmaintainingatemperatureof2560.1Cistobeused.Waterwaterglycerino

13、ilisusedastheheatingmediumthebathistobeprovidedwithheatingcirculatingthermostattingdevices.7.2BathSampleThermometersgraduatedin0.1Csubdivisionsstardizedftherangeofusetothe1ThesetestmethodsareunderthejurisdictionofASTMCom

14、mitteeD20onPlasticsisthedirectresponsibilityofSubcommitteeD20.22onCellularMaterialsPlasticsElastomers.CurrenteditionapprovedMay12015.PublishedJune2015.iginallyapprovedin1988.Lastpreviouseditionapprovedin2008asD487808.DOI

15、:10.1520D487815.2FreferencedASTMstardsvisittheASTMwebsitewww.astm.gcontactASTMCustomerServiceat.FAnnualBookofASTMStardsvolumeinfmationrefertothestard’sDocumentSummarypageontheASTMwebsite.3AvailablefromAmericanNationalSta

16、rdsInstitute(ANSI)25W.43rdSt.4thFloNewYkNY10036:www.ansi.g.ASummaryofChangessectionappearsattheendofthisstardCopyright?ASTMInternational100BarrHarbDrivePOBoxC700WestConshohockenPA194282959.UnitedStates118.Apparatus18.1Ad

17、ditionaldetailsofequipmentcanbefoundinSpecificationsD446.18.2ConstantTemperatureBathcapableofmaintainingatemperatureof2560.1C5060.1Cistobeused.Waterwaterglycerinoilanyothertransparentthermaltransferliquidistobeusedastheh

18、eatingmediumthebathistobeofsufficientdepthtobeprovidedwithheatingcirculatingthermostattingdevices.18.3Thermometersgraduatedin0.1Csubdivisionsstardizedftherangeofusetothenearest0.01C.ASTMSayboltViscosityThermometershaving

19、rangesfrom19to27C49to57CasspecifiedconfmingtotherequirementsfThermometersS117CS64CrespectivelyasprescribedinSpecificationE2251arerecommended.Anyotherthermometricdeviceofequalbetteraccuracyisalsoacceptable.18.4Glasscapill

20、aryviscometercalibratedbythemanufacturer.18.5Timingdevicecapableofreadingtothenearest0.1sbetterwithanaccuracyof60.07%ofthereadingwhentestedovertheintervalsof200900s.19.Solvents19.1MethanolAcetonereagentgrade.Anysolventin

21、whichthepolyoliscompletelymiscibleisacceptable.20.PreparationofSample20.1Thepreparationofahomogeneoussampleisofprimaryimptanceinviscositymeasurements.Thepresenceofairbubblestracesofextraneousmaterialaretobeavoided.Thesam

22、pleistobethoughlymixedthebubblesremovedbyheatinguseofasonicationbath.21.PreparationofApparatus21.1Theconstanttemperaturebathistobeheatedcooledtothedesiredtemperaturemaintainedpritosampleanalysis.21.2Theviscometertubeisto

23、becleandry.Thetubeistobesuspendedinthetemperaturebathusinganappropriatetubeholdersuchthatthemeasurementareaofthetubeisatleast20mmbelowthebathfluidsurfacethebottomofthetubeisatleast20mmfromthebottomofthebath.22.ChoiceofTe

24、mperature22.1Samplesthatareliquidhaveaviscosityoflessthan100000mPas(cP)at25Caretobemeasuredat25C.22.2Incasesofinterlabatystudieshigherviscositysamplesallpartiesaretoagreeuponasetmeasurementtemperature.23.ChoiceofViscomet

25、erTypeSize23.1Thetypeofviscometertobeuseddependsonthetransparencytheviscosityrangeofthematerialtobeanalyzed.TestMethodD445liststhetypesofviscometerstheirtypicalranges.FtransparentliquidpolyolsOstwaldtypesaretypicallyused

26、.23.2Thesizeofviscometertousedependsagainontheviscosityrangeofthematerialtobeanalyzed.SpecificationsD446listsspecificviscometertypesthesizesthatareavailable.Itisrecommendedthatthesizeedallowthesampletoflowfromthefirsttim

27、ingmarktothefinaltimingmarkinaminimumof200s.23.3Incasesofdisputebetweenpartiesregardingkinematicviscositymeasurementsallpartiesaretoagreeonthesametypesizeofviscometertobeusedinanyinterlabatystudies.24.Procedure24.1Thecon

28、stanttemperaturebathistobeheatedcooledtothedesiredtemperaturemaintainedpritosampleanalysis.24.2acleandryviscometercoveringtheappropriaterangefthesample.Suspendtheviscometerinthetemperaturebathsuchthatithangsverticallyina

29、lldirections(plumb).24.3getheviscometerwiththeproperamountofsampleaccdingtothedesignofthetube(RefertodocumentationaccompanyingtheviscometerSpecificationsD446).24.4Theviscometercontainingthesampleistoremaininthebathlongen

30、oughfthesampletoreachthebathtemperature.Thisistypicallydonebydrawingsampleupintothecapillarysideofthetubeviasuctionbulballowingthesampletoflowbackdowncompletelyviagravityflow.Afterseveralrepetitionsthesampleshouldbeatequ

31、ilibriumwiththebathtemperature.Asdifferentviscometertypessizeswillrequirevaryingequilibrationtimesdetermineasafetimebytrial.24.5Usingabulbothersuctiondeviceapplyavacuumtothecapillaryarmoftheviscometerdrawingthesamplehead

32、toapointafewmmabovethefirst(top)timingmark.Removethevacuumstartthetimingdeviceasthemeniscuspassesthefirsttimingmark.Allowtheliquidsampletoflowfreelyviagravitystoppingthetimingdeviceasthemeniscuspassesthesecondtimingmark.

33、Recdthistimeinsecondstotheneares0.1s.24.6Repeat24.5toobtainasecondmeasurement.Iftheduplicatesagreewithintherepeatabilitylistedin27.1repttheaverageoftheduplicates.Iftheduplicatesdonotagreerepeat24.5untiltwodeterminationsa

34、greewithinthatspecifiedin27.1.Thegreatestsourceofvariabilityistypicallyduetonotallowingenoughtimefthesampletemperaturetocometoequilibriumwiththebathtemperature(see24.4).24.7Cleantheviscometeraftersampleanalysisbyremoving

35、theviscometerfromthebathemptyingitscontents.Rinseseveraltimeswiththecleaningsolvent.Allowthetubetodrycompletelybystinginawarmovenbypassingdryairslowlythroughthetubeftwominutes.25.Calculations25.1Calculatethekinematicvisc