ASTM_D_3895_-_19.pdf

Designation:D389519Standard Test Method forOxidative-Induction Time of Polyolefins by DifferentialScanning Calorimetry1This standard is issued under the fixed designation D3895;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.Scope*1.1 This test method outlines a procedure for the determi-nation of oxidative-induction time(OIT)of polymeric materi-als by differential scanning calorimetry(DSC).It is applicableto polyolefin resins that are in a fully stabilized/compoundedform.1.2 The values stated in SI units are to be regarded as thestandard.1.3 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 and health practices and determine the applica-bility of regulatory limitations prior to use.Specific hazardsinformation is given in Section 8.NOTE1This standard and ISO 113576 2013 address the same subjectmatter,but differ in technical content.1.4 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:2D4703 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-lyzersE2935 Practice for Conducting Equivalence Testing inLaboratory Applications3.Terminology3.1 DefinitionsDefinitions of terms applying to thermalanalysis appear in Terminology E473.3.2 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.3.2.2 Abbreviations:3.2.3 HDPEhigh-density polyethylene.3.2.4 LDPElow-density polyethylene.3.2.5 LLDPElinear low-density polyethylene.3.2.6 OIToxidative induction time.4.Summary of Test Method4.1 The sample to be tested and the reference material areheated at a constant rate in an inert gaseous environment(nitrogen).When the specified temperature has been reached,the atmosphere is changed to oxygen maintained at the sameflow rate.The specimen is then held at constant temperatureuntil the oxidative reaction is displayed on the thermal curve.The OIT is determined from the data recorded during theisothermal period.The time interval from when the oxygenflow is first initiated to the oxidative reaction is referred to asthe 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 type of containment system used depends on theintended application use of the material being tested.Polyole-fins used in the wire and cable industry typically require copperor aluminum pans,whereas polyolefins used in geomembraneand vapor-barrier film applications exclusively use aluminumpans.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.30 on Thermal Properties.Current edition approved May 1,2019.Published June 2019.Originallyapproved in 1980.Last previous edition approved in 2014 as D3895 14.DOI:10.1520/D3895-19.2For 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.*A Summary of Changes section appears at the end of this standardCopyright 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.1 4.3 Unless otherwise specified,the analysis temperatureused in this test is set at 200.0C.For samples that haverelatively low or high stabilization levels,it is permissible toadjust the temperature(typically between 180 and 220C)toyield a thermal curve th