ASTM_D_2959_-_95_2009.pdf

Designation:D295995(Reapproved 2009)Standard Test Method forEthylene Oxide Content of Polyethoxylated NonionicSurfactants1This standard is issued under the fixed designation D2959;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 test method covers the determination of ethyleneoxide in polyethoxylated nonionic surfactants.It can also beused for compounds containing propylene oxide or any com-pounds(glycols and glycol and polyglycol ethers and esters)which form unstable 1,2-diiodides on reaction with hydriodicacid.NOTE1Compounds in which the oxyalkylene group is connected to anitrogen cannot be entirely decomposed.This can be used to determine thepercent of an ethoxylated surfactant in a mixture,if the ethylene oxidecontent of the ethoxylated surfactant is known.NOTE2This method reports results as percent ethylene oxide.If thismethod is applied to unknown compounds or compositions,the analystshould be aware of the possible presence of material other than ethyleneoxide.NOTE3For use on built syndet compositions the organic activeingredient must be isolated in accordance with Test Method D2358.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 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.Material SafetyData Sheets are available for reagents and materials.Reviewthem for hazards prior to usage.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD2358 Test Method for Separation ofActive Ingredient fromSurfactant and Syndet Compositions3.Summary of Test Method3.1 By cleaving nonionic surfactants containing polyethyl-ene oxide chains with hydriodic acid,the unstable 1,2-diiodoethane is formed.This vicinal diiodide decomposes toform ethylene and iodine.3.2 The percent ethylene oxide is determined by measuringthe amount of free iodine formed,since one mole of iodine isformed for each mole of ethylene oxide in the polyoxyalkylenechain.The free iodine is titrated with a standard sodiumthiosulfate solution.4.Apparatus(Fig.1)4.1 Heat Sources,two.The source of heat should be anelectric heater provided with a sliding rheostat or other meansof heat control.4.2 Flasks,two,100-mL,round bottom.Each flask shouldbe equipped with a standard ground-glass joint to accommo-date a vertical condenser,and with a side arm through whichcarbon dioxide can be passed to blanket the reaction mixture.4.3 Condensers,two,with standard joints to fit the flasks.4.4 Gas Bubbler,filled with dibutyl phthalate.4.5 Buret,50-mL,with 0.1-mL graduations.4.6 Pipet,5-mL.5.Reagents5.1 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 Chemical Society,1This method is under the jurisdiction of ASTM Committee D12 on Soaps andOther Detergents and is the direct responsibility of Subcommittee D12.12 onAnalysis and Specifications of Soaps,Synthetics,Detergents and their Components.Current edition approved Oct.1,2009.Published December 2009.Originallyapproved in 1971 as D2959 71 T.Last previous edition approved in 2003 asD2959 95(2003).DOI:10.1520/D2959-95R09.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 where such specifications are available.3Other 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.5.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean Type III reagent waterconforming to Sections 1,2,and 3 of Specification D1193.5.3 Carbon Dioxide or Nitrogen,cylinder gas.5.4 Lubricant for ground-glass joints.5.5 Dibutyl Phthalate.5.6 Glass Beads.5.7 Hydriodic Acid(55 to 58%)(suitable for methoxyldeterminations)The hydriodic acid(HI)should not containhypophosphorus acid(H3PO2)stabilizer.The free iodine con-tent should be less than 10 mL of 0.1 N sodium thiosulfatesolution/5 mL of HI.5.8 Hydrochloric Acid(sp gr 1.19)Concentrated hydro-chloric acid(HCl).5.9 Methanol.5.10 Potassium Dichromate(K2Cr2O7),primary standard.5.11 Potassium Iodide Solution(200 g/L)Dissolve 200 gof