ASTM_D_4669_-_07_2013e1.pdf

Designation:D466907(Reapproved 2013)1Standard 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 last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1NOTEReapproved with editorial changes in April 2013.1.Scope*1.1 These test methods measure the specific gravity ofpolyols.(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 standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE1There is no known ISO equivalent to this standard.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD4052 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 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 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 are suitable for quality control,specification testing,and research.The specific gravity isnecessary when converting kinematic viscosity to absoluteviscosity.TEST METHOD ASPECIFIC GRAVITY USING APYCNOMETER5.Apparatus5.1 Pycnometer,of 25 or 50-mL capacity,conical shapewith a capillary side arm overflow tube complete with astandard-taper512ground-glass joint to receive a ground-glassvented cap.A thermometer with a scale graduated from 12 to38C in 0.2-degree divisions joins the neck of the flask with astandard-taper1018ground-glass joint.The thermometer con-tained in the pycnometer shall be calibrated in accordance withSpecification E2251.5.2 Water Bath,capable of maintaining a temperature of25.0 6 0.05C during the test.5.3 Thermometer,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 Solution Prepare a saturatedsolution of chromic acid(CrO3)in concentrated sulfuric acid(H2SO4,sp gr 1.84).6.2 Acetone,reagent grade7.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.1These 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 Polyurethane Industry of the American Chemistry Council.Current edition approved April 1,2013.Published April 2013.Originallyapproved in 1987.Last previous edition approved in 2007 as D4669 07.DOI:10.1520/D4669-07R13E01.2For 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.*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 Since many polyols are hygroscopic,take care to provideminimum exposure to atmospheric moisture during the sam-pling.8.Procedure8.1 Clean the pycnometer by filling it with a chromic acidcleaning solution.Allow it to stand for a few hours,empty,andrinse well with distilled water.8.2 Fill the pycnometer with freshly boiled distilled watercooled to 22 to 24C,and set the pycnometer thermometer inplace carefully,avoiding trapping of air.Place the pycnometerin the water bath that has been maintained at 25.0 6 0.05C forat least 30 min and allow it to equilibrate to 25.0C.Wipe theoverflow from the side-arm capillary and cover with the ventedcap,remove from the bath,wipe dry,and weigh.8.3 Empty the pycnometer,rinse well with acetone and dryunder vacuum for 15 min.Weigh the pycnometer and subtractthe weight of the empty pycnometer from the weight whenfilled with wat