1、Designation:D234013Standard 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.1.2 This test method has been found applicable to thedetermination of peroxides
3、 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 The values stated in SI units are to be regarded asstandard.
4、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 and health practices and determine the applica-bilit
5、y of regulatory limitations prior to use.For specific hazardstatements,see Section 7.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD3437 Practice for Sampling and Handling Liquid CyclicProductsD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromat
6、ic 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 Test Method3.1 A specimen of styrene monomer is added to a solutionof iso
7、propanol 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 sodiumthiosulfate to a colorless end point.4.Significance and Use4.1 This
8、 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 condensers having inner and outer stan-dard taper joints.5.2 Electric H
9、ot 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 specifications of the Commit-tee on Analytical Reagents of the American Chem
10、ical Societywhere such specifications are available.4Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.1This test method is under the jurisdiction of ASTM Committee D16 onAromat
11、ic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.07 on Styrene,Ethylbenzene and C9 and C10 AromaticHydrocarbons.Current edition approved July 1,2013.Published August 2013.Originallyapproved in 1965.Last previous edition approved in 2009 as D2340 09.DOI:10.152
12、0/D2340-13.2For 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 Standardization Documents Order Desk,DO
13、DSSP,Bldg.4,SectionD,700RobbinsAve.,Philadelphia,PA19111-5098,http:/www.dodssp.daps.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 La
14、boratoryChemicals,BDH Ltd.,Poole,Dorset,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
15、,PA 19428-2959.United States1 6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water as definedby Type III of Specification D1193.6.3 Glacial Acetic Acid.6.4 Isopropyl Alcohol.6.5 Sodium Iodide Isopropyl Alcohol SolutionPrepare asaturated solution
16、of sodium iodide in isopropanol(approxi-mately 200 g NaI/L).6.6 Sodium Thiosulfate,Standard Solution(0.01 N)Dissolve 2.5 g of sodium thiosulfate(Na2S2O3 5H2O)and 0.1g of sodium carbonate(Na2CO3)in water and dilute to 1 L.Standardize against primary standard potassium dichromate(K2Cr2O7).7.Hazards7.1 Consult the latest OSHAregulations,suppliers MaterialSafety Data Sheets,and local regulations regarding all mate-rials used in this test method.7.2 Styrene monomer is flammable and polymerizes exo-th
