ASTM_D_4663_-_20.pdf

Designation:D466320Standard Test Method forPolyurethane Raw Materials:Determination of HydrolyzableChlorine of Isocyanates1This standard is issued under the fixed designation D4663;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 determines the hydrolyzable chlorinecontent of toluene-2,4-diisocyanate,toluene-2,6-diisocyanate,or mixtures of the two.It is acceptable to apply this test methodto other isocyanates of suitable solubility.(See Note 1.)Themain sources of hydrolyzable chlorine in the isocyanates arecarbamoyl chloride and dissolved phosgene.Both of thesecompounds react with alcohols and water,forming ureas,carbamates,carbon dioxide,and hydrochloric acid.(See Note2.)1.2 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.NOTE1It is possible that this test method is applicable to crudepolymeric isocyanates.However,the precision with crude polymericisocyanates has not been established.NOTE2This standard is identical to ISO 15028.1.3 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 Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Document2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1193 Specification for Reagent WaterE456 Terminology Relating to Quality and StatisticsE2935 Practice for Conducting Equivalence Testing inLaboratory Applications2.2 ISO Standards:ISO 15028 PlasticsAromatic Isocyanates for Use in theProduction of PolyurethanesDetermination of Hydroly-sable Chlorine33.Terminology3.1 DefinitionsTerms used in this standard are defined inaccordance with Terminology D883,unless otherwise speci-fied.For terms relating to precision and bias and associatedissues,the terms used in this standard are defined in accordancewith Terminology E456.3.2 Definitions of Terms Specific to This Standard:3.2.1 hydrolyzable chloridethe low-level chlorine-containing components of the isocyanate,such as carbamoylchlorides,which react with water or alcohol to form HCl.4.Summary of Test Method4.1 The hydrolyzable chlorine reacts with methanol,liber-ating hydrochloric acid.The titratable chlorides are thendetermined potentiometrically using a standard silver nitratesolution.5.Significance and Use5.1 This test method can be used for research or for qualitycontrol to characterize toluene diisocyanates.Hydrolyzablechlorine correlates with performance in some polyurethanesystems.6.Interferences6.1 Thiocyanate,cyanide,sulfide,bromide,iodide,or othersubstances capable of reacting with silver ions,as well assubstances capable of reducing silver ions in acid solution,willinterfere with the determination.7.Apparatus7.1 Weighing Bottle,or any device capable of weighing aliquid by difference to the nearest 0.1 g.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.22 on Cellular Materials-Plastics and Elastomers.Current edition approved April 1,2020.Published April 2020.Originallyapproved in 1987.Last previous edition approved in 2015 as D4663-15.DOI:10.1520/D4663-20.2For 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 American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.*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.7.2 Hot Plate,with magnetic stirrer.7.3 Potentiometric Titrator,or pH meter.7.4 Combination Silver Billet Electrode.8.Reagents and Materials8.1 Purity of ReagentsUse reagent grade chemicals in alltests.Unless otherwise indicated,it is intended that all reagentsconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society where suchspecifications are available.4Other grades may be used,pr