ASTM_D_8117_-_21.pdf

Designation:D811721Standard Test Method forOxidative Induction Time of Polyolefin Geosynthetics byDifferential Scanning Calorimetry1This standard is issued under the fixed designation D8117;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers a procedure for the determina-tion of the oxidative induction time(OIT)of polyolefingeosynthetics using differential scanning calorimetry.1.2 The focus of the test is on geomembranes,but geogrids,geonets,geotextiles,and other polyolefin-related geosyntheticsare also suitable for such evaluation.1.3 The values stated in SI units are to be regarded as thestandard.NOTE1This standard and ISO 11357-6 2013 address the same subjectmatter,but differ in technical content.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D4439 Terminology for GeosyntheticsD4703 Practice for Compression Molding ThermoplasticMaterials into Test Specimens,Plaques,or SheetsE473 Terminology Relating to Thermal Analysis and Rhe-ologyE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE967 Test Method for Temperature Calibration of Differen-tial Scanning Calorimeters and Differential Thermal Ana-lyzers3.Terminology3.1 Definitions:3.1.1 For definitions of terms applying to thermal analysis,refer to Terminology E473.3.1.2 For definitions of terms related to geosynthetics,referto Terminology D4439.3.2 Definitions of Terms Specific to This Standard:3.2.1 oxidative induction timea relative measure of amaterials resistance to oxidative decomposition;it is deter-mined by the thermoanalytical measurement of the timeinterval to onset of exothermic oxidation of a material at aspecified temperature in an oxygen atmosphere.3.3 Abbreviations:3.3.1 HDPEhigh-density polyethylene.3.3.2 LDPElow-density polyethylene.3.3.3 LLDPElinear low-density polyethylene.3.3.4 OIToxidative induction time.4.Summary of Test Method4.1 The sample to be tested is heated at a constant rate in aninert gaseous environment(nitrogen).When the specifiedtemperature has been reached,the atmosphere is changed tooxygen maintained at the same flow rate.The specimen is thenheld at constant temperature until the oxidative reaction isdisplayed on the thermal curve.The OIT is determined fromthe data recorded during the isothermal period.The timeinterval from when the oxygen flow is first initiated to theoxidative reaction is referred to as the induction period.4.1.1 The end of the induction period is signaled by anabrupt increase in the specimens evolved heat or temperatureand will be recorded as an exothermic event by a differentialscanning calorimeter(DSC).4.2 The test is conducted in open aluminum pans.5.Significance and Use5.1 The OIT is a qualitative assessment of the level(ordegree)of stabilization of the material tested.This test has the1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.02 on Endur-ance Properties.Current edition approved July 1,2021.Published July 2021.Originally approvedin 2017.Last previous edition approved in 2017 as D8117 17.DOI:10.1520/D8117-21.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1potential to be used as a quality control measure to monitor thestabilization level in formulated resin as received from asupplier,prior to extrusion.NOTE2The OIT measurement is an accelerated thermal-aging test,and as such can be misleading.Caution should be exercised in datainterpretation since oxidation reaction kinetics are a function of tempe