Designation:D3826−18StandardPracticeforDeterminingDegradationEndPointinDegradablePolyethyleneandPolypropyleneUsingaTensileTest1ThisstandardisissuedunderthefixeddesignationD3826;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoversthedeterminationofadegradation-endpoint(abrittlepoint)fordegradablepolyethylene/polypropylenefilmsandsheetinglessthan1.0mm(0.04in.)thick.Thispracticeisnotintendedfordeterminationoftherateordegreeofdegradationofapolyethylene/polypropylenefilmorsheet,butrather,toassesswheninthecourseofitsdegradationundersomecondition,abrittlepointisreached.Ifonewishestomonitortensileelongationduringthedegrada-tionprocess(suchaswhenthetensileelongationissignifi-cantlygreaterthan5%),TestMethodD882isrecommended.Thispracticeisnottobeconsideredtheonlywayofdeter-miningadegradation-endpoint.1.2Tensilepropertiesofplastics1.0mm(0.04in.)orgreaterinthicknessshallbedeterminedinaccordancewithTestMethodD638.1.3Useastaticweighing-constantrateofgripseparationtest.Thisprocedureemploysaconstantrateofseparationofthegripsholdingthesampleandastaticloadcell.NOTE1—Thisprocedureisbasedontheuseofgripseparationasameasureofextension;however,thedesirabilityofusingextensionindicatorsaccurateto61.0%orbetterasspecifiedinTestMethodD638isrecognized,andaprovisionfortheuseofsuchinstrumentationisincorporatedintheprocedure.1.4Thisprocedurehasbeensuccessfulfordeterminingthedegradationendpointofethylene-carbon-monoxidecopoly-mersandhasscreenedsuccessfullytwootheradditive-typepolyethylenesinaroundrobintest.1.5ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesinparenthesesareforinformationonly.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,he...
