1、Designation:D515519Standard Test Methods forPolyurethane Raw Materials:Determination of theIsocyanate Content of Aromatic Isocyanates1This standard is issued under the fixed designation D5155;the number immediately following the designation indicates the year oforiginal adoption or,in the case of re
2、vision,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 are used to measure the isocyanatecontent of aromatic isocyanates used as polyuretha
3、ne rawmaterials.1.1.1 Test Method AUnheated toluene-dibutylamine deter-mines the toluene diisocyanate content,the amine equivalentand the isocyanate content of refined toluene-2,4-diisocyanateand toluene-2,6-diisocyanate,or mixtures of the two.Otherisomers,if present,will be included in the determin
4、ation.Thistest method is also applicable to other isocyanates of suitablereactivity and solubility.1.1.2 Test Method BHeated toluene-dibutylamine deter-mines the amine equivalent and the isocyanate content of crudeor modified isocyanates derived from toluene diisocyanate,methylene di-(4-phenylisocya
5、nate)and polymeric(methylenephenylisocyanate).1.1.3 Test Method CUnheated trichlorobenzene-toluene-dibutylamine determines the amine equivalent and the isocya-nate content of crude or modified isocyanates derived fromtoluene diisocyanate,methylene-di-(4-phenylisocyanate)andpolymeric(methylene phenyl
6、isocyanate).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 establ
7、ish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE1Method C of this test method is equivalent to Method B ofISO 14896.1.4 This international standard was developed in accor-dance with internationally recognized prin
8、ciples 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 Plasti
9、csD1193 Specification for Reagent WaterE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)3E456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the P
10、recision of a Test MethodE2935 Practice for Conducting Equivalence Testing inLaboratory Applications2.2 ISO Standard:ISO 14896 Polyurethane Raw Materials-Determination ofIsocyanate Content3.Terminology3.1 DefinitionsTerms used in this standard are defined inaccordance with Terminology D883,unless ot
11、herwise 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 amine equivalentthe weight of sample that willcombine with 1.0-g equivalent weight
12、of dibutylamine.3.2.2 assaythe percent by weight of toluene diisocyanatepresent in the sample.3.2.3 isocyanate(NCO)contentthe percent by weight ofNCO groups present in the sample.4.Summary of Test Methods4.1 In all three test methods,the isocyanate sample isreacted with an excess amount of dibutylam
13、ine to form the1These 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.1,2019.Published August 2019.Originallyapproved in 1991.Last previous edit
14、ion approved in 2014 as D5155-141.DOI:10.1520/D5155-19.2For 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.3The last a
15、pproved version of this historical standard is referenced onwww.astm.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 accordanc
16、e 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 corresponding urea.The NCO content is determined from theamount of dibutylamine consumed in the reaction.The testmethods differ in the reaction conditions,or solvents used,orboth.4.1.1 Test Method AThe sample is added to an excessamount o
