Designation:D4202–92AnAmericanNationalStandardStandardTestMethodforThermalStabilityofPoly(VinylChloride)(PVC)Resin1ThisstandardisissuedunderthefixeddesignationD4202;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofthethermalstabilityofpoly(vinylchloride)(PVC)resins.1.2Aseachtypeandquantityofstabilizerwillhaveadifferenteffectonthermalstabilityofvariousresins,thistestmethodisnotintendedtopredictthethermalstabilityofagivenresininagivencompound.However,itmaybeusefulinqualityassuranceorin-plantqualitycontroltesting.1.3ThistestmethodhasnotbeenvalidatedforPVCcompounds.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyproblems,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimititionspriortouse.NOTE1—TherearenoISOstandardscoveringtheprimarysubjectofthisASTMstandard.2.ReferencedDocuments2.1ASTMStandards:D883TerminologyRelatingtoPlastics2D1600TerminologyforAbbreviatedTermsRelatingtoPlastics23.Terminology3.1Definitions:DefinitionsareinaccordancewithTermi-nologiesD883andD1600unlessotherwiseindicated.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1thermalstability—thetimeelapsedfromthemomentatwhichtheresinisexposedtothetesttemperatureuntilthefirstsignofevolutionofhydrogenchloride(decomposition)byindicatorpapercolorchange.4.SummaryofTestMethod4.1Thesampleofpowderorgranularistestedatthetesttemperatureinstillair,andthetime,requiredforthehydrogenchloridethatissplitofftochangethecolorofcongo-redpaperplacedabovethespecimen,ismeasured.5.SignificanceandUse5.1ThesplittingoffofhydrogenchlorideisoneoftheearliestindicationsofdecompositionofPVC;itistheprecur-sorofdiscolorationandotherdegradationphenomena.6.Apparatus6.1Cong...
