Designation:D7252−06(Reapproved2011)´1StandardTestMethodforPolyurethaneRawMaterials:DeterminationofMonomerandIsomersinIsocyanates1ThisstandardisissuedunderthefixeddesignationD7252;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ε1NOTE—ReapprovedwitheditorialchangesinSeptember2011.1.Scope1.1Thistestmethoddeterminesthepercentbyweightofmonomericisomersandtotalmonomerincrudeormodifiedisocyanates.Thetestmethodisapplicabletomethylenedi(phe-nylisocyanate)(MDI)andpolymeric(meththylenephenyliso-cyanate)(PMDI).(SeeNote1.)1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.NOTE1—ThereisnoknownISOequivalenttothisstandard.2.ReferencedDocuments2.1ASTMStandards:2D883TerminologyRelatingtoPlasticsE682PracticeforLiquidChromatographyTermsandRela-tionshipsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethod3.Terminology3.1FordefinitionsoftermsusedinthesetestmethodsseeTerminologyD883.4.SummaryofTestMethod4.1Thesampleisreacted(derivatized)withmethanoltoformamixtureofmethylurethanes.Theurethanesmixtureisthenseparatedbynormalphasehighperformanceliquidchromatography(HPLC).Theseparated,derivatizedisomersarequantifiedthroughtheuseofaninternalstandard.5.SignificanceandUse5.1Thistestmethodcanbeusedforresearchorforqualitycontroltocharacterizeisocyanatesusedinpolyurethaneprod-ucts.6.Apparatus6.1HighPerformanceLiquidChromatograph,consistingof:6.1.1Binary(orgreater)solventpump,capableofmain-tainingapulse-freeflowrateof1-3millilitresperminute6.1.2Sampleinjector,automaticormanual,capableofreproduciblyinjectinga2microlitrevolume6.1.3Columnheater,capableofmaintainingatempe...
