Designation:D4273−18StandardTestMethodforPolyurethaneRawMaterials:DeterminationofPrimaryHydroxylContentofPolyetherPolyols1ThisstandardisissuedunderthefixeddesignationD4273;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Carbon-13NuclearMagneticResonanceSpectroscopy(13CNMR)measurestheprimaryhydroxylcontentofethyleneoxide(EO)-propyleneoxide(PO)polyetherpolyolsusedinpreparingflexiblepolyurethanefoams.Thismethodisbestsuitedforpolyetherpolyolswithprimaryhydroxylcontentsof10to90%.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.NOTE1—ThereisnoknownISOequivalenttothisstandard.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D883TerminologyRelatingtoPlasticsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethodE2977PracticeforMeasuringandReportingPerformanceofFourier-TransformNuclearMagneticResonance(FT-NMR)SpectrometersforLiquidSamples3.Terminology3.1Definitions—Fordefinitionsoftermsthatappearinthismethod,refertoTerminologyD883andPracticeE2977.4.SummaryofTestMethod4.1Peaksoftheprimaryandsecondaryhydroxylcarbonsofpolyetherpolyolsusedinflexiblepolyurethanefoamsarewell-resolvedinhigh-resolution13CNMRspectra.Thepri-maryhydroxylcontentisdeterminedfromtheratiooftheprimaryhydroxylareatothetotalhydroxyl(p...
