1、Designation:D739918Standard Test Method forDetermination of the Amount of Polypropylene inPolypropylene/Low Density Polyethylene Mixtures UsingInfrared Spectrophotometry1This standard is issued under the fixed designation D7399;the number immediately following the designation indicates the year ofor
2、iginal 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 uses an infrared spectrometer fordetermining the a
3、mount of polypropylene(PP)physicallymixed in with low density polyethylene usually for recyclingpurposes.NOTE1Quantitative determinations require several standard mixturesin the concentration range of interest and well defined baseline anchoringpoints.See Practice E168 for guidance.1.2 This standard
4、 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.NOTE2There is no know
5、n ISO equivalent to this standard.1.3 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
6、Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-ticsD2238 Test Methods forAbsorbance of Polyethylene Due toMethyl Groups at 1378 cm1E131 Terminology Relating t
7、o Molecular SpectroscopyE168 Practices for General Techniques of Infrared Quanti-tative AnalysisE932 Practice for Describing and Measuring Performance ofDispersive Infrared SpectrometersE1421 Practice for Describing and Measuring Performanceof Fourier Transform Mid-Infrared(FT-MIR)Spectrom-eters:Lev
8、el Zero and Level One TestsIEEE/ASTM SI-10 Standard for Use of the InternationalSystem of Units(SI):The Modern Metric System3.Terminology3.1 DefinitionsFor definitions of plastics terms used inthis test method,see Terminology standards D883 and D1600.3.2 TerminologyUnits,symbols,and abbreviations us
9、ed inthis test method appear in Terminology E131 or IEEE/ASTMSI-10.4.Summary of Test Method4.1 Thin films representing a typical portion of the materialare analyzed with an infrared spectrophotometer using twoabsorbance bandsone characteristic for PP and one forLDPE.The ratio of these two absorbenci
10、es is used to assess thepresence of polypropylene.4.2 For quantitative determinations,several standards withknown concentrations of PP in LDPE bracketing the range ofinterest are needed to develop a calibration curve.In addition,baseline placement process is defined so as to produce repeat-able resu
11、lts.5.Significance and Use5.1 In recycling PP and LDPE,it is important to the endproduct properties as well as to the processing conditions toknow what the composition of the mixture is.6.Interferences6.1 Presence of materials other than PPor LDPE in a samplecan cause error in measurement.6.2 Inhomo
12、geneity of sample is known to cause falsereadings.It is recommended to verify the sample homogeneityby measuring at least three different areas of the sample.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analyt
13、ical Methods.Current edition approved April 1,2018.Published April 2018.Originallyapproved in 2008.Last previous edition approved in 2008 as D7399-08,which waswithdrawn February 2017 and reinstated in April 2018.DOI:10.1520/D7399-18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,
14、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
15、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 O
16、rganization Technical Barriers to Trade(TBT)Committee.1 7.Apparatus7.1 Infrared Spectrophotometer,either double beam or aFourier transform.7.1.1 Double-Beam Infrared Spectrophotometer,capable ofat least 4 cm-1spectral resolution as defined in Practice E932.The instrument shall be capable of scale expansion along thewavelength axis.7.1.2 Fourier Transform Infrared Spectrometer(FTIR),ca-pable of at least 4 cm-1resolution.The instrument shall becapable of scale expansion along the wavelength axis.A