Designation:D5629−16StandardTestMethodforPolyurethaneRawMaterials:DeterminationofAcidityinLow-AcidityAromaticIsocyanatesandPolyurethanePrepolymers1ThisstandardisissuedunderthefixeddesignationD5629;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodmeasurestheacidity,expressedasppmofhydrochloricacid(HCl),inaromaticisocyanateorpolyure-thaneprepolymersamplesofbelow100ppmacidity.Thetestmethodisapplicabletoproductsderivedfromtoluenediiso-cyanateandmethylenedi(phenylisocyanate)(seeNote1).RefertoTestMethodD6099fordeterminationofacidityinmoderate-tohigh-acidityaromaticisocyanates.1.2ThevaluesstatedinSIunitsaretoberegardedasthestandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.NOTE1—ThisstandardisequivalenttoISO14898,MethodB.2.ReferencedDocuments2.1ASTMStandards:2D883TerminologyRelatingtoPlasticsD6099TestMethodforPolyurethaneRawMaterials:Deter-minationofAcidityinModeratetoHighAcidityAromaticIsocyanatesE180PracticeforDeterminingthePrecisionofASTMMethodsforAnalysisandTestingofIndustrialandSpe-cialtyChemicals(Withdrawn2009)3E691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethod2.2ISOStandards:4ISO14898Plastics—AromaticIsocyanatesforUseintheProductionofPolyurethane—DeterminationofAcidity3.Terminology3.1Definitions—Theterminologyinthistestmethodfol-lowsthestandardterminologydefinedinTerminologyD883.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1acidity,n—theacidstrengthofasampleexpressedinppmHCl.4.SummaryofTestMethod4.1Theisocyanateismixedwithanexcessofn-propanol,acosolventandaknownamountofHCl.Additionalacidisreleased...
