1、Designation:D465914Standard Test Methods forPolyurethane Raw Materials:Determination of SpecificGravity of Isocyanates1This standard is issued under the fixed designation D4659;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year
2、 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 determine the specific gravity oftoluenediisocyanateandcrudemethylene-bis-(4-phenylisocyanate).Thes
3、e test methods also are applicable tomany other liquids.(See Note 1.)1.1.1 Test Method ASpecific gravity by pycnometer,forhigh-accuracy determination.1.1.2 Test Method BSpecific gravity by hydrometer,for aless accurate,but rapid,determination.1.2 The values stated in SI units are to be regarded asst
4、andard.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 applic
5、a-bility of regulatory limitations prior to use.For specificwarning and precautionary statements see Section 7.NOTE1There is no known ISO equivalent to this standard.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD891 Test Methods for Specific Gravity,Apparent,of Liqu
6、idIndustrial ChemicalsD1193 Specification for Reagent WaterD4052 Test Method for Density,Relative Density,and APIGravity of Liquids by Digital Density MeterE100 Specification for ASTM HydrometersE202 Test Methods for Analysis of Ethylene Glycols andPropylene GlycolsE2251 Specification for Liquid-in-
7、Glass ASTM Thermom-eters with Low-Hazard Precision Liquids3.Terminology3.1 DefinitionsFor definitions of terms used in these testmethods see Terminology D883.3.2 Definitions of Terms Specific to This Standard:3.2.1 specific gravitythe ratio of the weight in air of agiven volume of the material at a
8、stated temperature to theweight in air of an equal volume of water at a statedtemperature.It shall be expressed as specific gravity,25/25C,indicating that the sample and reference water were bothmeasured at 25C.4.Significance and Use4.1 These test methods can be used for research or forquality contr
9、ol to characterize isocyanates used in polyurethaneproducts.4.2 Ageneral test method for specific gravity using a digitaldensity meter,which applies to isocyanates as well as otherliquids is published in Test Method D4052.TEST METHOD ASPECIFIC GRAVITY BYPYCNOMETER5.Apparatus5.1 Pycnometer,of 25 or 5
10、0-mLcapacity,conical shape witha capillary side arm overflow tube having a standard-taper 5/12ground-glass joint and a ground-glass vented cap.A thermom-eter graduated from 12 to 38C in 0.2 divisions attached to theneck of the flask by a standard-taper 10/18 ground-glass joint.This thermometer is to
11、 be calibrated using the ASTM ther-mometer specified in 5.3.5.2 Water BathA water bath maintained at 25 6 0.05C.5.3 ThermometerAnASTMlow-softeningpointthermometer,calibrated from 2 to+80C,which meets therequirements for Thermometer S15C in Specification E2251.5.4 Analytical BalanceAbalance having a
12、sensitivity of atleast 0.1 mg.1These 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 March 1,2014.Published March 2014.Originallyapproved in 1987.La
13、st previous edition approved in 2009 as D4659-09.DOI:10.1520/D4659-14.2For 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 webs
14、ite.*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.Reagents and Materials6.1 Purity of ReagentsUse reagent grade chemicals in alltests.Unless otherwise indicated,it is in
15、tended that all reagentsconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society where suchspecifications are available.3Other grades can be used,pro-vided it is ascertained that the reagent is of sufficiently highpurity to permit its use without lessenin
16、g the accuracy of thedetermination.6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water as definedby Type IV or better of Specification D1193.6.3 Chromic Acid Cleaning SolutionPrepare a saturatedsolution of chromic acid(CrO3)in concentrated sulfuric acid(H2SO4,sp gr 1.84).7.Sampling7.1 Since organic isocyanates react with atmosphericmoisture,take special precautions in sampling.Usual samplingmethods,even when conducted rapidly,can cause conta
