1、Designation:D466918Standard Test Method forPolyurethane Raw Materials:Determination of SpecificGravity of Polyols1This standard is issued under the fixed designation D4669;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of l
2、ast 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 the specific gravity ofpolyols.Test MethodAmeasures the specific gravity of polyolsusing a pycno
3、meter and Test Method B lists a reference formeasuring the specific gravity of liquids using a density meterthat is applicable to polyols(see Note 1).1.2 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 sta
4、ndard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE1There is no known ISO equivalent to this standard.1.3 This international standard was developed in accor-dance with internationally recognized princi
5、ples 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:2D883 Terminology Relating to Plastics
6、D4052 Test Method for Density,Relative Density,and APIGravity of Liquids by Digital Density MeterE2251 Specification for Liquid-in-Glass ASTM Thermom-eters with Low-Hazard Precision LiquidsE202 Test Methods for Analysis of Ethylene Glycols andPropylene Glycols3.Terminology3.1 DefinitionsFor definiti
7、ons 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 stated temperature to theweight in air of an equal volume of water at a statedtemperature.It shall
8、 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 are suitable for quality control,specification testing,and research.The specific gravity isnecessary when converting kinematic viscosity to ab
9、soluteviscosity.TEST METHOD ASPECIFIC GRAVITY USING APYCNOMETER5.Apparatus5.1 Pycnometer,of 25 or 50-mLcapacity,conical shape witha capillary side arm overflow tube complete with a standard-taper512ground-glass joint to receive a ground-glass ventedcap.A thermometer with a scale graduated from 12 to
10、 38C in0.2-degree divisions joins the neck of the flask with a standard-taper1018ground-glass joint.The thermometer contained in thepycnometer shall be calibrated in accordance with Specifica-tion E2251.5.2 Water Bath,capable of maintaining a temperature of25.0 6 0.05C during the test.5.3 Thermomete
11、r,an ASTM Low Softening Point Ther-mometer having a range from-2 to+80C and conforming tothe requirements for Thermometer S15C as prescribed inSpecification E2251.5.4 Analytical Balance,sensitive to 0.1 mg.6.Reagents6.1 Chromic Acid Cleaning SolutionPrepare a saturatedsolution of chromic acid(CrO3)i
12、n concentrated sulfuric acid(H2SO4,sp gr 1.84).6.2 Acetone,reagent grade1These test methods are under the jurisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.22 on CellularMaterials-Plastics and Elastomers.It was recommended toASTM by the Center forthe
13、Polyurethane Industry of the American Chemistry Council.Current edition approved April 1,2018.Published April 2018.Originallyapproved in 1987.Last previous edition approved in 2013 as D4669 07(2013)1.DOI:10.1520/D4669-18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact AS
14、TM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken
15、,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
16、Technical Barriers to Trade(TBT)Committee.1 7.Sampling7.1 High molecular weight polyester and polyether polyolscontain molecules covering an appreciable range of molecularweights.These have a tendency to fractionate during solidifi-cation.Unless the material is a finely ground solid it isnecessary to melt(using no higher temperature than necessary)and mix the polyol well before removing a sample for analysis.Since many polyols are hygroscopic,take care to provideminimum exposure to atmospheric m