Designation:D5510–94(Reapproved2001)StandardPracticeforHeatAgingofOxidativelyDegradablePlastics1ThisstandardisissuedunderthefixeddesignationD5510;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticeisintendedtodefinetheexposurecondi-tionsofplasticsatvarioustemperatureswhenexposedsolelytohotairforextendedperiodsoftime.Onlytheproceduresforheatexposurearespecified,notthetestmethodorspecimen.Theeffectofheatonanyparticularpropertymaybedeter-minedbyselectionoftheappropriatetestmethodandspeci-men;however,itisrecommendedthatPracticeD3826beusedtodeterminetheembrittlementendpoint,whichisdefinedasthatpointinthehistoryofamaterialwhen75%ofthespecimenstestedhaveatensileelongationatbreakof5%orlessataninitialstrainrateof0.1mm/mmmin.1.2Thispracticeshouldbeusedasaguideforcomparingthethermal-agingcharacteristicsofmaterialsasmeasuredbythechangeinsomepropertyofinterest(thatis,embrittlementbymeansoflossofelongation).ItisverysimilartoPracticeD3045butisintendedforuseinevaluatingplasticsdesignedtobeoxidizedeasilyafteruse.TheexposuretimesusedforthispracticewillbesignificantlyshorterthanthoseusedforPracticeD3045.1.3Thetypeofovenusedcanaffecttheresultsobtainedfromthispractice.Theusercanuseoneoftwomethodsforovenexposure.Theresultsbasedononemethodshouldnotbemixedwiththosebasedontheother.1.3.1ProcedureA:Gravity-ConvectionOven—Recommendedforfilmspecimenshavinganominalthicknessnotgreaterthan0.25mm(0.010in.).1.3.2ProcedureB:Forced-VentilationOven—Recommendedforspecimenshavinganominalthicknessgreaterthan0.25mm(0.010in.).1.4Thispracticerecommendsproceduresforcomparingthethermalagingcharacteristicsofmaterialsatasingletempera-ture.Recommendedproceduresfordeterminingthethermalagingcharacteristicsofamaterialataseriesoftemperaturesforthepurposeofestimatingtimetoadefinedpropertyc...
