1、Designation:D487714Standard 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 las
2、t 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
3、-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
4、 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.NOTE1This standard is
5、 equivalent to ISO 6271-1:2004.2.Referenced Documents2.1 ASTM Standards:3D883 Terminology Relating to PlasticsD1193 Specification for Reagent WaterD1209 Test Method for Color of Clear Liquids(Platinum-Cobalt Scale)D5386 Test Method for Color of Liquids Using TristimulusColorimetry2.2 ISO Standards:I
6、SO 6271-1:2004 Clear liquidsEstimation of colour bythe platinum-cobalt scalePart 1:Visual method43.Terminology3.1 For definitions of terms used in this test method seeTerminology D883.4.Summary of Test Method4.1 The color of the material to be tested is compared to aseries of platinum cobalt color s
7、tandards,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
8、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
9、 and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.5Other grades
10、can be used,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 IV or better o
11、f Specification D1193.1This 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 Aug.1,2014.Published September 2014.Originallyapproved in 1988.Last previo
12、us edition approved in 2010 as D4877-10.DOI:10.1520/D4877-14.2See 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
13、 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.5Reagent Chemicals,American Chemical Society S
14、pecifications,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.Pharmacopeial Convention,Inc
15、.(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 7.3 Cobaltous Chloride Hexahydrate(CoCl2 6H2O).7.4 Concentrated Hydrochloric Acid(sp.gr.1.19).7.5 Potass
16、ium Chloroplatinate(K2PtCl6).8.Sampling8.1 Since organic isocyanates react with atmosphericmoisture,take special precautions in sampling.Usual samplingmethods,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 may include the development of occupational asthmaand o