ASTM_D_4877_-_19.pdf

Designation:D487719Standard Test Method forPolyurethane Raw Materials:Determination of APHA Colorin Isocyanates1This standard is issued under the fixed designation D4877;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 measures the color of clear liquids.Itis applicable only to materials whose color-producing bodieshave light-absorption characteristics similar to those of theplatinum cobalt color standards used.2(See Test MethodD1209 and Note 1.)Suitable isocyanates include toluenediisocyanate,and pure or modified monomeric methylenedi(phenylisocyanate).1.2 The values stated in SI units are to be regarded asstandard.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 and ISO 6271-1 address the same subjectmatter,but differ in technical content.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:3D883 Terminology Relating to PlasticsD1193 Specification for Reagent WaterD1209 Test Method for Color of Clear Liquids(Platinum-Cobalt Scale)D4890 Test Methods for Polyurethane Raw Materials:De-termination of Gardner and APHA Color of PolyolsD5386 Test Method for Color of Liquids Using TristimulusColorimetryE456 Terminology Relating to Quality and StatisticsE2935 Practice for Conducting Equivalence Testing inLaboratory Applications2.2 ISO Standards:ISO 6271-1 Clear liquidsEstimation of colour by theplatinum-cobalt scalePart 1:Visual method43.Terminology3.1 Terms used in this standard are defined in accordancewith Terminology D883,unless otherwise specified.For termsrelating to precision and bias and associated issues,the termsused in this standard are defined in accordance with Terminol-ogy E456.4.Summary of Test Method4.1 The color of the material to be tested is compared to aseries of platinum cobalt color standards,designated by mg ofPt/mLof standard solution.The results are reported as the colorstandard,which best matches the sample(Note 2).NOTE2Test methods for measuring the platinum-cobalt color ofliquids instrumentally are availablefor example,Test Method D5386.5.Significance and Use5.1 This test method can be used for research or for qualitycontrol to characterize isocyanates used in polyurethane prod-ucts.5.2 For toluene diisocyanate,results from this test methodcan relate to reactivity or performance in polyurethane sys-tems.6.Apparatus6.1 Nessler Tubes,matched,100-mL tall-form.7.Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended that1This 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 Aug.1,2019.Published August 2019.Originallyapproved in 1988.Last previous edition approved in 2014 as D4877-14.DOI:10.1520/D4877-19.2See Standard Methods for the Examination of Water,Sewage,and IndustrialWastes,AM.Public Health Assn.,1015 15th St.NW Washington,DC 20005.3For 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.4Available 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.1 all reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch 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 indicat