Designation:D6099−13StandardTestMethodforPolyurethaneRawMaterials:DeterminationofAcidityinModeratetoHighAcidityAromaticIsocyanates1ThisstandardisissuedunderthefixeddesignationD6099;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethoddeterminestheacidity,expressedaspartspermillion(ppm)ofHCl,inaromaticisocyanatesamplesofgreaterthan100–ppmacidity.Thetestmethodisapplicabletoproductsderivedfromtoluenediisocyanateandmethylene-bis-(4–phenylisocyanate)(seeNote1).NOTE1—ThistestmethodisequivalenttoISO14898,TestMethodA.2.ReferencedDocuments2.1ASTMStandards:2D883TerminologyRelatingtoPlasticsE180PracticeforDeterminingthePrecisionofASTMMethodsforAnalysisandTestingofIndustrialandSpe-cialtyChemicals(Withdrawn2009)3E691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethod2.2ISOStandards:ISO14898Plastics—Aromaticisocyanatesforuseintheproductionofpolyurethane—Determinationofacidity43.Terminology3.1Definitions—TermsusedinthistestmethodareinaccordancewithTerminologyD883.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1acidity,n—theacidstrengthofasampleexpressedinppmHCl.4.SummaryofTestMethod4.1Theisocyanateismixedwithanexcessofmethanolandacosolvent.Additionalacidisreleasedintothesolventsystemduringurethaneformation.Theacidistitratedpotentiometri-callywithmethanolicKOH,andtheaciditypresentintheisocyanatesampleiscalculatedfromthetiter.5.SignificanceandUse5.1Thistestmethodcanbeusedforresearchorforqualitycontroltocharacterizearomaticisocyanatesandprepolymersofmoderatetohighacidity.Aciditycorrelateswithperfor-manceinsomepolyurethanesystems.6.Apparatus6.1250-mLBeakers.6.250-mLPipetorRepipet,ClassAvolumetric.6.3100-mLPipetorRepipet,ClassAvolumetric.6.4AutomaticTitrationEquipment,capableofinflectiondetectionandstirringthesamplewhile,...
