ASTM_D_4661_-_13.pdf

Designation:D466113Standard 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 and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE1There is no known ISO equivalent to this standard.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 Isocyanates3.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 oxygen bomb.4.1.2 Test Method BThe sample is combusted at atmo-spheric pressure in a Schniger oxygen flask.35.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 suchspecifications are available.4Other grades may be used,pro-vided 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 react with atmosphericmoisture,take special precautions in sampling.Usual sampling1These 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 Nov.1,2013.Published November 2013.Originallyapproved in 1987.Last previous edition approved in 2009 as D4661-09.DOI:10.1520/D4661-13.2For 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.3For information on the Schniger flask,refer to Microchemie,SpringerPublishers,Vienna,Austria,Vol 42,1955,p.123,or Vol 43,1956,p.869.4Reagent 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,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmaceutical 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 States1 methods,even when conducted rapidly,can cause contamina-tion of the sample with insoluble urea.Therefore,blanket thesample with dry air or nitrogen at all times.(WarningManydiisocyanates are known or suspected sensitizers.Over-exposure to diisocyanates can lead to adverse health effects,which include the development of occupational asthma andother respiratory,skin and eye effects.Engineering controlsand/or personal protective equipment,i