ASTM_D_3826_-_18.pdf

Designation:D382618Standard Practice forDetermining Degradation End Point in DegradablePolyethylene and Polypropylene Using a Tensile Test1This standard is issued under the fixed designation D3826;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 practice covers the determination of a degradation-end point(a brittle point)for degradable polyethylene/polypropylene films and sheeting less than 1.0 mm(0.04 in.)thick.This practice is not intended for determination of the rateor degree of degradation of a polyethylene/polypropylene filmor sheet,but rather,to assess when in the course of itsdegradation under some condition,a brittle point is reached.Ifone wishes to monitor tensile elongation during the degrada-tion process(such as when the tensile elongation is signifi-cantly greater than 5%),Test Method D882 is recommended.This practice is not to be considered the only way of deter-mining a degradation-end point.1.2 Tensile properties of plastics 1.0 mm(0.04 in.)orgreater in thickness shall be determined in accordance withTest Method D638.1.3 Use a static weighing-constant rate of grip separationtest.This procedure employs a constant rate of separation ofthe grips holding the sample and a static load cell.NOTE1This procedure is based on the use of grip separation as ameasure of extension;however,the desirability of using extensionindicators accurate to 61.0%or better as specified in Test Method D638is recognized,and a provision for the use of such instrumentation isincorporated in the procedure.1.4 This procedure has been successful for determining thedegradation end point of ethylene-carbon-monoxide copoly-mers and has screened successfully two other additive-typepolyethylenes in a round robin test.1.5 The values stated in SI units are to be regarded as thestandard.The values in parentheses are for information only.1.6 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.1.7 There is no equivalent ISO standard.1.8 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:2D374/D374M Test Methods for Thickness of Solid Electri-cal InsulationD618 Practice for Conditioning Plastics for TestingD638 Test Method for Tensile Properties of PlasticsD882 Test Method for Tensile Properties of Thin PlasticSheetingD883 Terminology Relating to PlasticsD5208 Practice for Fluorescent Ultraviolet(UV)Exposureof Photodegradable PlasticsD5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions of TermsFor definitions of terms used inthis specification associated with plastics issues refer to theterminology contained in Terminology D883.3.2 Definitions:3.2.1 Definitions of terms and symbols relating to tensiontesting of plastics appear in the Annex to Test Method D638.3.2.2 line grips,nin tensile testing machines,grips havingfaces designed to concentrate the entire gripping force along asingle line perpendicular to the direction of testing stress.3.2.3 tear failure,nin tensile testing of films,a failurecharacterized by fracture initiating at one edge of the specimen1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.96 on Environmentally DegradablePlastics and Biobased Products.Current edition approved Nov.1,2018.Published November 2018.Originallyapproved in 1991.Last previous edition approved in 2013 as D3826 98(2013).DOI:10.1520/D3826-18.2For 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.1 and progressing across the specimen at a rate slow enough to