1、Designation: D 4659 09Standard Test Methods forPolyurethane Raw Materials: Determination of SpecificGravity of Isocyanates1This standard is issued under the fixed designation D 4659; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、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 determine the specific gravity oftoluenediisocyanate and crude methylene-bis-(4-phenyl
3、isocyanate). These 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 a
4、re to be regarded asstandard. 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 practice
5、s and determine the applica-bility of regulatory limitations prior to use. For specificwarning and precautionary statements see Section 7.NOTE 1There is no equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:2D 883 Terminology Relating to PlasticsD 891 Test Methods for Specific Gravity
6、, Apparent, ofLiquid Industrial ChemicalsD 1193 Specification for Reagent WaterE1 Specification for ASTM Liquid-in-Glass ThermometersE 100 Specification for ASTM HydrometersE 202 Test Methods for Analysis of Ethylene Glycols andPropylene Glycols3. Terminology3.1 DefinitionsFor definitions of terms u
7、sed in these testmethods see Terminology D 883.3.2 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 expresse
8、d 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 control to characterize isocyanates used in polyurethaneproducts.TEST METHOD ASPECIFIC GRAVITY BYPYCNOMETER5. App
9、aratus5.1 Pycnometer, of 25 or 50-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-
10、glass joint.This thermometer is to 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 ThermometerAn ASTM low-softening point ther-mometer, calibrated from 2 to +80C, which meets therequirements for Thermometer 15C in Specification E1.5.
11、4 Analytical BalanceAbalance having a sensitivity of atleast 0.1 mg.6. Reagents and Materials6.1 Purity of ReagentsUse reagent grade chemicals in alltests. Unless otherwise indicated, it is intended that all reagentsconform to the specifications of the Committee on AnalyticalReagents of the American
12、 Chemical Society where such1These 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 Feb. 1, 2009. Published February 2009. Originallyapproved in 19
13、87. Last previous edition approved in 2003 as D 4659 - 03.2For 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.1*A
14、 Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.specifications are available.3Other grades can be used, pro-vided it is ascertained that the reagent is of sufficiently hi
15、ghpurity to permit its use without lessening 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 D 1193.6.3 Chromic Acid Cleaning SolutionPrepare a saturatedsoluti
16、on of chromic acid (CrO3) in concentrated sulfuric acid(H2SO4, sp gr 1.84).7. Sampling7.1 Since organic isocyanates react with atmospheric mois-ture, take special precautions in sampling. Usual samplingmethods, even when conducted rapidly, can cause contamina-tion of the sample with insoluble urea.
17、Therefore, blanket thesample with dry air or nitrogen at all times. (WarningManydiisocyanates are known or suspected sensitizers. Over-exposure to diisocyanates can lead to adverse health effects,which may include the development of occupational asthmaand other respiratory, skin, and eye effects. En
18、gineering con-trols, or personal protective equipment, or both, includingrespiratory, skin, and eye protection, are to be used when thereis a potential for over-exposure to diisocyanates. The productsuppliers Material Safety Data Sheet (MSDS) provides moredetailed information about potential adverse
19、 health effects andother important safety and handling information. Alwaysfollow the specific instructions provided on the MSDS.)8. Test Conditions8.1 Since isocyanates react with moisture, keep laboratoryhumidity low, preferably around 50 % relative humidity.9. Procedure9.1 Clean the pycnometer by
20、filling it with chromic acidcleaning solution and by allowing it to stand for a few hours.Empty the pycnometer and rinse well with distilled water.9.2 Fill the pycnometer with freshly boiled distilled waterthat has been cooled to 22 to 24C. Insert the thermometer intothe pycnometer without trapping
21、air bubbles. Place the pyc-nometer in a water bath at 25 6 0.05C and allow it and itscontents to equilibrate for at least 30 min. Wipe the overflowfrom the side-arm capillary and cover it with the vented cap.Remove the pycnometer from the bath, wipe dry, and weigh.9.3 Empty the pycnometer and rinse
22、it with alcohol, thenwith ether. Remove the ether and dry the pycnometer undervacuum for 15 min. Weigh the pycnometer. Determine theweight, W, of the water at 25.0C in air by subtracting theweight of the empty pycnometer from the weight of thepycnometer filled with water.NOTE 2Other drying technique
23、s can be used if ether is to be avoided.It must be established that for any alternative drying method, a clean anddry pycnometer results.9.4 Carry out the rest of the procedure in a ventilated hood.The sample for testing must be completely liquid. If the samplecontains solid toluene diisocyanate, wa
24、rm it in its originalcontainer until it becomes liquid. Rapidly cool the liquid to 22to 24C and fill the pycnometer, while minimizing exposure ofthe sample to air.9.5 Insert the thermometer into the pycnometer withouttrapping air bubbles. Cover the side arm with the vented capand allow the pycnomete
25、r to equilibrate in the water bath for atleast 30 min. Wipe the overflow from the side arm capillaryand cover it with the cap vented. Remove the pycnometer fromthe bath, wipe dry, and weigh. To obtain the weight, S, of thesample at 25.0C, subtract the weight of the empty pycnometerfrom the weight wh
26、en filled with sample.10. Calculation10.1 Calculate the specific gravity at 25/25C as follows:Specific gravity, 25/25C 5SWwhere:S = sample used, g (see 9.5), andW = water in the pycnometer, g (see 9.3).11. Precision and Bias11.1 Attempts to develop a precision and bias statement forthis test method
27、have not been successful. Data on precisionand bias cannot be given for this reason. Anyone wishing toparticipate in the development of precision and bias data cancontact the Chairman, Subcommittee D20.22 (SectionD20.22.01), ASTM, 100 Barr Harbor Drive, West Consho-hocken, PA 19428-2959.11.2 Test Me
28、thod E 202 is similar and does include preci-sion data. Precision statements from E 202 are restated belowas an estimate of the precision for this test method.11.2.1 RepeatabilityIt has been estimated that duplicateresults by the same analyst are to be considered suspect if theydiffer by 0.0002 unit
29、s.11.2.2 ReproducibilityIt has been estimated that resultsreported by different laboratories are to be considered suspectif they differ by 0.0008 units.11.3 BiasThere are no recognized standards by which toestimate the bias of this test method.TEST METHOD BSPECIFIC GRAVITY BYHYDROMETER12. Apparatus1
30、2.1 HydrometerAn ASTM hydrometer with a specificgravity range from 1.195 to 1.255 at 15.6/15.6C conformingto the requirements for Hydrometer 115H in SpecificationE 100.12.2 Hydrometer CylinderA clear glass cylinder with aninside diameter at least 25.4 mm 1 in. larger than thehydrometer and tall enou
31、gh so that there is at least 1 in.between the bottom of the cylinder and the bottom of thehydrometer after equilibration at 25C.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American
32、 Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.D 4659 09212.3 ThermometerSee 5.3.12.4 Water BathSee 5.2.13. Sampling13.1 Since organic
33、isocyanates react with atmosphericmoisture, take special precautions in sampling. Usual samplingmethods, 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. (WarningManydiisocyanates are known or
34、 suspected sensitizers. Over-exposure to diisocyanates can lead to adverse health effects,which may include the development of occupational asthmaand other respiratory, skin, and eye effects. Engineering con-trols, or personal protective equipment, or both, includingrespiratory, skin, and eye protec
35、tion, are to be used when thereis a potential for over-exposure to diisocyanates. The productsuppliers Material Safety Data Sheet (MSDS) provides moredetailed information about potential adverse health effects andother important safety and handling information. Alwaysfollow the specific instructions
36、 provided on the MSDS.)14. Test Conditions14.1 Since isocyanates react with moisture, keep laboratoryhumidity low, preferably around 50 % relative humidity15. Procedure15.1 The sample for test must be completely liquid. If thesample is turbid, warm it in its original container until itbecomes clear,
37、 then cool it to 22 to 24C. Carry out this entireprocedure in a well-ventilated hood.15.2 To avoid forming air bubbles, slowly pour the sampleinto the dry hydrometer cylinder. Remove any air bubblesadhering to the surface by touching them with a piece of cleanfilter paper. Place the cylinder in the
38、water bath. Stir thecontents of the cylinder, being careful to avoid formation of airbubbles. When the temperature of the sample is 24.8C, slowlyand carefully lower the hydrometer into the sample liquid to alevel two small scale divisions below that at which it will floatand then release the hydrome
39、ter.Allow the hydrometer to cometo rest and make sure it does not touch the walls of the cylinder.When the temperature of the sample reaches 25.0C, read thegravity by sighting below the level of the liquid and slowlyraising up until the surface of the sample, first seen as adistorted ellipse, seems
40、to become a straight line cutting thehydrometer scale.15.3 Determine the temperature of the sample just beforeand just after reading the hydrometer.16. Calculation16.1 Calculate the specific gravity at 25/25C as follows(Note 3):Specific gravity, 25/25C 5 observed value10.0021NOTE 3The correction fac
41、tor +0.0021 is applied to correct the readingto 25/25C because the hydrometer was standardized at 15.6/15.6C.17. Precision and Bias17.1 Attempts to develop a precision and bias statement forthis test method have not been successful. Data on precisionand bias cannot be given for this reason. Anyone w
42、ishing toparticipate in the development of precision and bias data cancontact the Chairman, Subcommittee D20.22 (SectionD20.22.01), ASTM, 100 Barr Harbor Drive, West Consho-hocken, PA 19428-2959.17.2 Test Method D 891 is similar and does include preci-sion data. Precision statements from D 891 are r
43、estated belowas an estimate of the precision for this test method.17.2.1 RepeatabilityIt has been estimated that duplicateresults by the same analyst are to be considered suspect if theydiffer by 0.0005 units.17.2.2 ReproducibilityIt has been estimated that resultsreported by different laboratories
44、are to be considered suspectif they differ by 0.0021 units.17.3 There are no recognized standards by which to esti-mate the bias of this test method.18. Keywords18.1 density; hydrometer; isocyanates; polyurethane rawmaterials; pycnometer; specific gravitySUMMARY OF CHANGESCommittee D20 has identifie
45、d the location of selected changes to this standard since the last issue(D 4659 - 03) that may impact the use of this standard. (February 1, 2009)(1) Revised 1.3 to list Section 7.(2) Revised Section 7 for explanation of and effects ofmoisture (7.1), and Warning.(3) Added Sections 13 (Sampling) and
46、14 (Test Conditions).Renumbered Sections 13-15 to 15-17.(4) Removed non-mandatory language from 5.1, 6.1, 11.2.1,11.2.2, 17.1, 17.2.1, and 17.2.2.D 4659 093ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard
47、. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed
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49、chnical 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 Standards, 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
