1、Designation:D234018Standard Test Method forPeroxides in Styrene Monomer1This standard is issued under the fixed designation D2340;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 indic
2、ates 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 perox-ide content of styrene monomer reported as hydrogen peroxide.1.2 This test method has been found applicable to
3、 thedetermination of peroxides in styrene monomer in the range of1 to 60 mg/kg.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 UnitsThe values stated in SI u
4、nits are to be regardedas standard.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 enviro
5、nmental practices and deter-mine the applicability of regulatory limitations prior to use.For specific hazard statements,see Section 7.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles
6、 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:2D1193 Specification for Reagent WaterD3437 Practice for Sampling and Handling Liquid CyclicProductsD680
7、9 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 Specifications2.2 Other Documents:OSHA Regulations,29 CFR paragraphs 1910.1000 and1910.120033.Summary of Tes
8、t Method3.1 A specimen of styrene monomer is added to a solutionof isopropanol and acetic acid.A saturated solution of sodiumiodide in isopropanol is added and the solution refluxed.Theperoxides present liberate iodine from sodium iodide quantita-tively.The liberated iodine is then titrated with sod
9、iumthiosulfate to a colorless end point.4.Significance and Use4.1 This test method is suitable for determining the quantityof peroxides in styrene monomer both for quality control andquality assurance of the product.5.Apparatus5.1 Erlenmeyer Flasks,glass-stoppered,500-mL,equippedwith 300-mm Liebig c
10、ondensers having inner and outer stan-dard taper joints.5.2 Electric Hot Plate with totally enclosed heating unit.5.3 Boiling Chips.6.Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specif
11、ications of the Commit-tee on Analytical Reagents of the American Chemical Societywhere such specifications are available.4Other grades may beused,provided it is first ascertained that the reagent is of1This test method is under the jurisdiction of ASTM Committee D16 onAromatic,Industrial,Specialty
12、and Related Chemicals and is the direct responsi-bility of Subcommittee D16.07 on Styrene,Ethylbenzene and C9 and C10AromaticHydrocarbons.Current edition approved Jan.1,2018.Published January 2018.Originallyapproved in 1965.Last previous edition approved in 2013 as D2340 13.DOI:10.1520/D2340-18.2For
13、 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 DLA Document Services,Building 4/D,700 Robbins Ave.,Ph
14、iladelphia,PA 19111-5094,http:/quicksearch.dla.mil.4Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dors
15、et,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.*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 inte
16、rnational 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 sufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagen
