1、Designation: D 4669 98 (Reapproved 2002)e1Standard Test Method forPolyurethane Raw Materials: Determination of SpecificGravity of Polyols1This standard is issued under the fixed designation D 4669; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEEditorially updated the organizational reference in Footnote 1 in November 2002.1. Scope *1.1 Th
3、is test method measures the specific gravity of poly-ols using a pycnometer. (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 practic
4、es and determine the applica-bility of regulatory limitations prior to use.NOTE 1There is no equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:D 883 Terminology Relating to Plastics2E 1 Specification for ASTM Thermometers3E 202 Test Methods for Analysis of Ethylene Glycols andPropyle
5、ne Glycols.43. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod see Terminology D 883.3.2 Description of Term 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 eq
6、ual 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 This test method is suitable for quality control, as aspecification test, and for research. It is necessary
7、 whenconverting from kinematic to absolute viscosity.5. Apparatus5.1 Pycnometer, of 25 or 50-mL capacity, conical shapewith a capillary side arm overflow tube complete with astandard-taper512 ground-glass joint to receive a ground-glassvented cap. A thermometer with a scale graduated from 12 to38C i
8、n 0.2-degree divisions joins the neck of the flask with astandard-taper1018 ground-glass joint. The thermometer con-tained in the pycnometer shall be calibrated in accordance withSpecification E 1.5.2 Water Bath, capable of maintaining a temperature of25.0 6 0.05C during the test.5.3 Thermometer, an
9、 ASTM Low Softening Point Ther-mometer having a range from -2 to +80C and conforming tothe requirements for Thermometer 15C as prescribed inSpecification E 1.5.4 Analytical Balance, sensitive to 0.1 mg.6. Reagents6.1 Chromic Acid Cleaning SolutionPrepare a saturatedsolution of chromic acid (CrO3) in
10、 concentrated sulfuric acid(H2SO4, sp gr 1.84).7. Sampling7.1 Polyesters and polyethers usually contain moleculescovering an appreciable range of molecular weights. Thesehave a tendency to fractionate during solidification. Unless thematerial is a finely ground solid it is necessary to melt (usingno
11、 higher temperature than necessary) and mix the resin wellbefore removing a sample for analysis. Since many polyols arehygroscopic, take care to provide minimum exposure toatmospheric moisture during the sampling.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the
12、 direct responsibility of Subcommittee D20.22 on Cellular MaterialsPlastics and Elastomers. It was recommended to ASTM by the Alliance for thePolyurethane Industrys Polyurethane Raw Materials Analysis Committee.Current edition approved November 10, 2002. Published January 2003. Origi-nally approved
13、in 1987. Last previous edition approved in 1996 as D 4669 98.2Annual Book of ASTM Standards, Vol 08.01.3Annual Book of ASTM Standards, Vol 14.03.4Annual Book of ASTM Standards, Vol 15.05.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor
14、Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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
15、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. Wipe the overflow from the side-arm capillaryand cover with the vented cap, remove from the bath, wipe dry,
16、and weigh.8.3 Empty the pycnometer, rinse successively with alcoholand ether, remove the ether vapor, and dry under vacuum for 15min. Weigh the pycnometer and subtract the weight of theempty pycnometer from the weight when filled with water inorder to obtain the weight, W, of the contained water at
17、25Cin air.8.4 The sample for test must be completely liquid. If thesample contains solid polyol, warm the entire sample in theoriginal container until it becomes liquid. Then cool the sampleto 22 to 24C and quickly fill the pycnometer with it, allowingit minimal exposure to the atmosphere.8.5 Insert
18、 the thermometer carefully, avoiding trapping ofair. Cover the side arm with the vented cap, remove from thebath, wipe dry, and weigh. Subtract the weight of the emptypycnometer from the weight when filled with the sample inorder to obtain the weight, S, of the contained sample at25.0C.9. Calculatio
19、n9.1 Calculate the specific gravity at 25/25C as follows:S/W 5Specific gravity, 25/25Cwhere:S = sample used, g, andW = water in the pycnometer, g.10. Precision and Bias10.1 Attempts to develop a precision and bias statement forthis test method have not been successful. Data on precisionand bias cann
20、ot be given for this reason. Anyone wishing toparticipate in the development of precision and bias datashould contact the Chairman, Subcommittee D20.22 (SectionD20.22.01), ASTM 100 Barr Harbor Drive, West Consho-hocken, PA 19428-2959.10.2 Test Methods E 202 is similar and does include preci-sion dat
21、a. Precision statements from Test Methods E 202 arerestated below as an estimate of the precision for this testmethod.10.2.1 RepeatabilityIt has been estimated that duplicateresults by the same analyst should be considered suspect if theydiffer by 0.0002 units.10.2.2 ReproducibilityIt has been estim
22、ated that resultsreported by different laboratories should be considered suspectif they differ by 0.0008 units.10.3 BiasThere are no recognized standards by which toestimate the bias of this test method.11. Keywords11.1 density; polyols; polyurethane raw materials; specificgravitySUMMARY OF CHANGEST
23、his section identifies the location of selected changes to this test method. For the convenience of the user.Committee D20 has highlighted those changes that may impact the use of this test method. This section may alsoinclude descriptions of the changes or reasons for the changes, or both.D 4669 98
24、(02)e1:(1) Changed reference information in Footnote 1.D 4669 98:(1) Section 2.1Added references to Test Methods E 202.(2) FootnotesInserted footnote 4.(3) Section 10Replaced the precision and bias statementwith quote and reference to the precision and bias statement ofTest Methods E 202.ASTM Intern
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26、heir own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand shoul
27、d be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Stand
28、ards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 4669 98 (2002)e12
