Designation:D6814−02(Reapproved2013)StandardTestMethodforDeterminationofPercentDevulcanizationofCrumbRubberBasedonCrosslinkDensity1ThisstandardisissuedunderthefixeddesignationD6814;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoverstheprocedurefordeterminingpercentdevulcanizationfromcrosslinkdensitymeasurementsofdevulcanizedrubberandcontrolcrumbrubberinthelaboratory.Percentdevulcanizationisaquantitativedetermi-nation.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D297TestMethodsforRubberProducts—ChemicalAnaly-sis3.Terminology3.1Definitions:3.1.1rubber,n—naturalorsyntheticelastomerthathasbeenchemicallycrosslinked/vulcanizedtoenhanceitsusefulprop-erties.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1devulcanization,n—aprocessofbreakingdownchemicalcrosslinksincuredrubber.4.SummaryofTestMethod4.1ThecrumbrubbersampleisextractedinhotacetoneperTestMethodsD297anddriedat7062°Cinaforced-ventilatingairovenfor1661h.Thedriedcrumbrubberisswolleninasolvent(forexamplesofpolymer-solventpairing,seeAppendixX1)withreagentgradepurity,selectionbasedonrubbertype,for24hatroomtemperature.Thesolventisreplacedwithfreshsolventthreetimesduringtheswellingprocess.Afterswelling,thesolventiswipedquicklyfromthesurfaceoftheswollencrumbrubberusingacleanpapertowel.Measuretheweightoftheswollensampleinapreweightedandtaredweighingbottlewithclosure.Dryitat7062°Cinaforced-ventilatingairovenfor1661h.Cooltoroomtemperatureinadesiccatora...
