ASTM_D_4661_-_18.pdf

Designation:D466118Standard Test Methods forPolyurethane Raw Materials:Determination of Total Chlorinein Isocyanates1This standard is issued under the fixed designation D4661;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 These test methods determine the total chlorine contentof aromatic isocyanates used as polyurethane raw materials.The difference between the total chlorine content and thehydrolyzable chlorine content(see Test Method D4663)is ameasure of the amount of o-dichlorobenzene and other ring-substituted chlorinated products that are present.Both proce-dures are applicable to a variety of organic compounds but theamount of sample used may have to be varied.(See Note 1.)1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE1This standard is identical to ISO 26603.1.4 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:2D883 Terminology Relating to PlasticsD1193 Specification for Reagent WaterD4663 Test Method for Polyurethane Raw Materials:Deter-mination of Hydrolyzable Chlorine of Isocyanates2.2 ISO Standard:3ISO 26603 PlasticsAromatic isocyanates for use in theproduction of polyurethanesDetermination of totalchlorine3.Terminology3.1 DefinitionsFor definitions of terms used in these testmethods see Terminology D883.4.Summary of Test Method4.1 In each test method,the organic matter in the sample isdestroyed by combustion with oxygen,the organically com-bined chlorine being converted to ionic chloride.The chlorideis determined potentiometrically by titration with silver nitrate(AgNO3)solution.4.1.1 Test Method AThe sample is combusted in a pres-surized ignition vessel.4.1.2 Test Method BThe sample is combusted at atmo-spheric pressure in a Schniger oxygen flask.45.Significance and Use5.1 These test methods can be used for research or forquality control to determine the total chlorine content ofaromatic isocyanates.In some instances total chlorine contentmay correlate with performance in polyurethane systems.6.Interferences6.1 Bromine and iodine,if present,will react with the silvernitrate(AgNO3)solution leading to an erroneously high totalchlorine value.7.Reagents and Materials7.1 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 such1These test methods are under the jurisdiction of ASTM Committee D20 onPlastics and are the direct responsibility of Subcommittee D20.22 on CellularMaterials-Plastics and Elastomers.Current edition approved Aug.1,2018.Published August 2018.Originallyapproved in 1987.Last previous edition approved in 2013 as D4661-13.DOI:10.1520/D4661-18.2For 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.4For information on the Schniger flask,refer to Microchemie,SpringerPublishers,Vienna,Austria,Vol 42,1955,p.123,or Vol 43,1956,p.869.*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 specifications are available.5Other grades are acceptable,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.7.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water as definedby Type I of Specification D1193.8.Sampling8.1 Since organic isocyanates