1、Designation:D488921Standard Test Methods forPolyurethane Raw Materials:Determination of Viscosity ofCrude or Modified Isocyanates1This standard is issued under the fixed designation D4889;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revisi
2、on,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(Aand B)determine the viscosity ofcrude or modified isocyanates.They are applicable to pr
3、oductsderivedfromtoluenediisocyanate,methylenedi(phenylisocyanate),and polymeric(methylene phenylisocya-nate)(see Note 1).NOTE1Test method A includes a procedure for measuring dynamicviscosity using a rotational instrument.Test method B is a generalprocedure for kinematic viscosity of isocyanate.1.2
4、 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
5、the applicability of regulatory limitations prior to use.For specific hazards statement,see Warning at the end of 5.1.NOTE2Test Method A is equivalent to ISO 3219,Test Method B isequivalent to ISO 3104.1.4 This international standard was developed in accor-dance with internationally recognized princ
6、iples 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:2D445 Test Method for Kinematic Visco
7、sity of Transparentand Opaque Liquids(and Calculation of Dynamic Viscos-ity)D446 Specifications and Operating Instructions for GlassCapillary Kinematic ViscometersD883 Terminology Relating to PlasticsE456 Terminology Relating to Quality and StatisticsE2251 Specification for Liquid-in-Glass ASTM Ther
8、mom-eters with Low-Hazard Precision LiquidsE2935 Practice for Conducting Equivalence Tests for Com-paring Testing Processes2.2 ISO Standards:3ISO 3104 Petroleum ProductsTransparent and OpaqueLiquidsDetermination of Kinematic Viscosity and Cal-culation of Dynamic ViscosityISO 3219 PlasticsPolymers/Re
9、sins in the Liquid State oras Emulsions or DispersionsDetermination of ViscosityUsing a Rotational Viscometer with Defined Shear Rate3.Terminology3.1 Terms used in this standard are defined in accordancewith Terminology D883,unless otherwise specified.For termsrelating to precision and bias and asso
10、ciated issues,the termsused in this standard are defined in accordance with Terminol-ogy E456.4.Significance and Use4.1 These test methods can be used for research,qualitycontrol,or specification tests to characterize isocyanates usedin polyurethane products.4.2 Viscosity measures the resistance of
11、a fluid to uniformcontinuous flow without turbulence or other forces.4.3 Some isocyanates exhibit non-Newtonian behavior un-der certain conditions.Whenever possible,generate results forcomparison under the same conditions,that is,the samespindle/speed combination for rotational viscosity and thesame
12、 tube size for kinematic viscosity.5.Sampling5.1 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 Cel
13、lularMaterials-Plastics and Elastomers.Current edition approved Jan.15,2021.Published January 2021.Originallyapproved in 1988.Last previous edition approved in 2015 as D4889-15.DOI:10.1520/D4889-21.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at
14、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 en
15、d 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 theDevelop
16、ment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1methods,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.(WarningDiisocyanates are eye,skin and respiratory irritants at concen-trations above the occupational exposure limit(TLV or PEL).Diisocyanates can cause skin and respiratory sensitization(asthma)in
