ASTM_D_4890_-_13.pdf

Designation:D489013Standard Test Methods forPolyurethane Raw Materials:Determination of Gardner andAPHA Color of Polyols1This standard is issued under the fixed designation D4890;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 measure visually the color of clearpolyester and polyether liquids.They apply only to materialswhose colors have light-absorption characteristics similar tothose of the standards.An alternative method is Test MethodD1209(see Note 1).1.2 UnitsThe values stated in SI units are to be regardedas standard.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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE1Test Method A of this standard is equivalent to ISO 6271-1.Test Method B of this standard is equivalent to ISO 4630-1.2.Referenced Documents2.1 ASTM Standards:2D883 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 TristimulusColorimetryD6166 Test Method for Color of Pine Chemicals and Re-lated Products(Instrumental Determination of GardnerColor)E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1164 Practice for Obtaining Spectrometric Data for Object-Color Evaluation2.2 ISO Standards:3ISO 4630-1 Clear LiquidsEstimation of Colour by theGardner Colour ScalePart 1:Visual MethodISO 4630-2 Clear LiquidsEstimation of Colour by theGardner Colour ScalePart 2:Spectroscopic MethodISO 6271-1 Clear LiquidsEstimation of Color by thePlatinum-Cobalt ScalePart 1:Visual MethodISO 6271-2 Clear LiquidsEstimation of Color by thePlatinum-Cobalt ScalePart 2:Spectroscopic Method3.Terminology3.1 For definitions of terms used in these test methods seeTerminology D883.4.Summary of Test Method4.1 In Test Method A,the color of the material to be testedis compared to a series of color standards with definedchromicity coordinates,prepared on one of three ways.Theresults are reported as the color standard,which best matchesthe sample.4.2 In Test Method B,the color of the material to be testedis compared to a series of platinum-cobalt color standards,designated by mg of Pt/mLof standard solution.The results arereported as the color standard,which best matches the sample(see Note 2).NOTE2Color of liquids are also measured by visible spectroscopyand the results converted to any of several color scales.These results areconverted to theAPHAscale by appropriate manipulations,as for examplein Test Method D5386 and ISO 6271-2.These results are converted to theGardner scale by appropriate manipulations,as for example in TestMethod ISO 4630-2.5.Significance and Use5.1 These test methods are suitable for quality control,asspecification tests,and for research.Color is an importantproperty of urethane products.1These test methods are under the jurisdiction of Committee D20 on Plastics andare the direct responsibility of Subcommittee D20.22 on Cellular Materials-Plasticsand Elastomers.Current edition approved April 1,2013.Published April 2013.Originallyapproved in 1988.Last previous edition approved in 2006 as D4890-06.DOI:10.1520/D4890-13.2For 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.3Available 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 States1 6.Sampling6.1 Polyesters and polyethers usually contain moleculescovering an appreciable range of molecular weights.Thesehave a tendency to fractionate during solidification.Unless thematerial is a liquid or finely ground solid it is necessary to melt(using no higher temperature than necessary)and mix the resinwell before removing a sample for analysis.Many polyols arehygroscopic and care should be taken to provide minimumexposure to atmospheric moisture during the sampling.7.Purity of Reagents7.1 Purity of ReagentsReagent-grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifi