ASTM_D_5272_-_08_2013.pdf

Designation:D527208(Reapproved 2013)Standard Practice forOutdoor Exposure Testing of Photodegradable Plastics1This standard is issued under the fixed designation D5272;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 defines test conditions applicable whenPractices D1435 and G7 are employed for the outdoor expo-sure testing of photodegradable plastics.1.2 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.NOTE1There is no known ISO equivalent to this standard.2.Referenced Documents2.1 ASTM Standards:2D882 Test Method for Tensile Properties of Thin PlasticSheetingD883 Terminology Relating to PlasticsD1435 Practice for Outdoor Weathering of PlasticsD3593 Test Method for Molecular Weight Averages/Distri-bution of Certain Polymers by Liquid Size-ExclusionChromatography(Gel Permeation Chromatography GPC)Using Universal Calibration(Withdrawn 1993)3D3826 Practice for Determining Degradation End Point inDegradable Polyethylene and Polypropylene Using a Ten-sile TestE772 Terminology of Solar Energy ConversionG7 Practice for Atmospheric Environmental Exposure Test-ing of Nonmetallic MaterialsG169 Guide for Application of Basic Statistical Methods toWeathering TestsG183 Practice for Field Use of Pyranometers,Pyrheliom-eters and UV Radiometers3.Terminology3.1 The terminology given in Terminology E772 and Ter-minology D883 is applicable to this practice.4.Significance and Use4.1 When discarded as litter,articles made using photode-gradable plastics are subject to attack by daylight(particularlysolar-ultraviolet radiation),oxygen,heat,and water.The 5exposure angle used in this practice represents typical condi-tions for degradation experienced by litter.4.2 This practice requires characterization of the duration ofexposure in terms of solar-ultraviolet radiation.Solar-ultraviolet radiation varies considerably as a function oflocation and time of year.This can cause dramatic differencesin the time required to produce a specified level of degradationin a polymer.Daro4has shown that when the same lot ofpolyethylene containing an iron-salt prodegradant is exposed atvarious times of the year in a single location,the time requiredto produce an average of two chain scissions per moleculevaried by over 130%.Daro,and Zerlaut and Anderson5haveshown that this variability can be significantly reduced whentotal solar or solar-ultraviolet radiation,or both,is used tocharacterize the exposure increments.4.3 In addition to variations in level of daylight and solar-ultraviolet radiation,there are significant differences intemperature,and moisture stresses between different locations,and between different years,or periods within a single year,ata single location.Because of this variability,results from thistest cannot be used to predict the absolute rate at whichphotodegradable plastics degrade.Results from this test can beused to compare relative rates of degradation for materialsexposed at the same time in the same location.Results frommultiple exposures of a common lot of material(duringdifferent seasons over several years)at different sites can beused to compare the relative rates at which a particularphotodegradable plastic will degrade in each location.1This 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 April 1,2013.Published April 2013.Originallyapproved in 1992.Last previous edition approved in 2008 as D5272-08.DOI:10.1520/D5272-08R13.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.4Daro,A.,et al,“Degradation of Polymer Blends IV,Natural Weathering of LowDensity and Linear Low Density Polyethylene,”European Polymer Journal,Vol 26,No.1,1990,pp.4752.5Zerlaut,G.L.,and Anderson,T.A.,“Ultraviolet Radiation as a TimingTechnique for Outdoor Weathering of Materials,”Society ofAutomotive Engineers,SAE Technical Paper Number 850348,1985.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 NOTE2An inherent limitation in solar-radiation measurements is thatthey do not reflect the effects of variations in temperature and moistureexposure,which often can be as important as solar