ASTM_D_7977_-_19.pdf

Designation:D797719Standard Test Methods forPolymer Content of AMS(-Methylstyrene)1This standard is issued under the fixed designation D7977;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 covers the determination of the poly-mer content of AMS(-Methystyrene).Dimers and trimers arenot measured by these test methods.1.2 This test method has been found applicable to determin-ing the polymer content of AMS in concentrations up to 15mg/kg with an LOQ of 0.6 mg/kg and an LOD of 0.2 mg/kg.Samples containing more than 15 mg/kg of polymer must besuitably diluted before measurement.1.3 In determining the conformance of the test results usingthis method to applicable specifications,results shall berounded off in accordance with the rounding-off method ofPractice E29.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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.For specific hazard statements,see Section 8.1.6 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:2D3437 Practice for Sampling and Handling Liquid CyclicProductsD6367 Specification for AMS(-Methylstyrene)D6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 Other Document:3OSHA Regulations,29 CFR paragraphs 1910.1000 and1910.1200TEST METHOD ADETERMINATION OF POLYMERIN-METHYLSTYRENE VIASPECTROPHOTOMETER3.Summary of Test Method3.1 This test method utilizes the fact that AMS polymerspresent in the monomers are insoluble in methanol.Thepolymer content of AMS monomer is determined by measure-ment of the degree of turbidity produced by the addition of drymethanol to the AMS sample.4.Significance and Use4.1 This test method can be used for determining polymerconcentrations in AMS monomer.4.2 This test method will not detect dimers and trimers.4.3 This test method can be used for plant control and forspecification analysis.5.Interferences5.1 Small changes in turbidity may occur with time.It is,therefore,important that the absorbance of calibration mixturesand samples be determined after standing the same length oftime.5.2 Hexane is used for two reasons:5.2.1 To block out any color in the AMS,and5.2.2 To indicate high levels of dissolved water in theAMS.1These test methods are under the jurisdiction of ASTM Committee D16 onAromatic,Industrial,Specialty and Related Chemicals and is the direct responsi-bility of Subcommittee D16.07 on Styrene,Ethylbenzene and C9 and C10AromaticHydrocarbons.Current edition approved June 1,2019.Published June 2019.Originallyapproved in 2014.Last previous edition approved in 2014 as D7977 14.DOI:10.1520/D7977-19.2For 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.3Available from U.S.Government Printing Office Superintendent of Documents,732 N.Capitol St.,NW,Mail Stop:SDE,Washington,DC 20401,http:/www.access.gpo.gov.*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 5.3 Water content was found to have a slight impact on themeasurement of polymer in AMS solution.When the waterconcentration is below 260 ppm,its effect on the measurementof polymer in AMS solution is negligible.6.Apparatus6.1 Class A Volumetric Pipets,10 and 15-mL.6.2 Bottles or Flasks,of suitable size equipped with glassstoppers.6.3 Spectrophotometer or Photometer Cells,with 100 to150-mm light path.6.4 Spectrophotometer or Photomete