ASTM D4659-98
(Test Method)Standard Test Methods for Polyurethane Raw Materials Determination of Specific Gravity of Isocyanates
Standard Test Methods for Polyurethane Raw Materials Determination of Specific Gravity of Isocyanates
SCOPE
1.1 These test methods determine the specific gravity of toluene-2,4-diisocyanate and toluene-2,6-diisocyanate or mixtures of the two. These test methods also are applicable to many other liquids. (See Note 1.)
1.1.1 Test Method A -Specific gravity by pycnometer, for high-accuracy determination.
1.1.2 Test Method B -Specific gravity by hydrometer, for a less accurate, but rapid, determination.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific warning and precautionary statements see Notes 2 and 3. Note 1-There is no equivalent ISO standard.
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Designation: D 4659 – 98
Standard Test Methods for
Polyurethane Raw Materials: Determination of Specific
Gravity of Isocyanates
This standard is issued under the fixed designation D 4659; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope * E 202 Test Methods for Analysis of Ethylene Glycols and
Propylene Glycols
1.1 These test methods determine the specific gravity of
toluenediiosocyanate and crude methylene-bis-(4-
3. Terminology
phenylisocyanate). These test methods also are applicable to
3.1 Definitions:
many other liquids. (See Note 1.)
3.1.1 For definitions of terms used in these test methods see
1.1.1 Test Method A—Specific gravity by pycnometer, for
Terminology D 883.
high-accuracy determination.
3.2 Description of Term Specific to This Standard:
1.1.2 Test Method B—Specific gravity by hydrometer, for a
3.2.1 specific gravity—the ratio of the weight in air of a
less accurate, but rapid, determination.
given volume of the material at a stated temperature to the
1.2 The values stated in SI units are to be regarded as the
weight in air of an equal volume of water at a stated
standard. The values given in parentheses are for information
temperature. It shall be expressed as specific gravity, 25/25°C,
only.
indicating that the sample and reference water were both
1.3 This standard does not purport to address all of the
measured at 25°C.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Significance and Use
priate safety and health practices and determine the applica-
4.1 These test methods can be used for research or for
bility of regulatory limitations prior to use. For specific
quality control to characterize isocyanates used in polyurethane
warning and precautionary statements see Notes 2 and 3.
products.
NOTE 1—There is no equivalent ISO standard.
TEST METHOD A—SPECIFIC GRAVITY BY
2. Referenced Documents
PYCNOMETER
2.1 ASTM Standards:
5. Apparatus
D 883 Terminology Relating to Plastics
5.1 Pycnometer, of 25 or 50-mL capacity, conical shape with
D 891 Test Methods for Specific Gravity, Apparent, of
a capillary side arm overflow tube having a standard-taper 5/12
Liquid Industrial Chemicals
D 1193 Specification for Reagent Water ground-glass joint and a ground-glass vented cap. A thermom-
eter graduated from 12 to 38°C in 0.2° divisions attached to the
E 1 Specification for ASTM Thermometers
E 100 Specification for ASTM Hydrometers neck of the flask by a standard-taper 10/18 ground-glass joint.
This thermometer should be calibrated using the ASTM
thermometer specified in 5.3.
5.2 Water Bath—A water bath maintained at 25 6 0.05°C.
5.3 Thermometer—An ASTM low-softening point ther-
mometer, calibrated from −2 to +80°C, which meets the
These test methods are under the jurisdiction of ASTM Committee D-20 on
requirements for Thermometer 15C in Specification E 1.
Plastics and are the direct responsibility of Subcommittee D20.22 on Cellular
Plastics. 5.4 Analytical Balance—A balance having a sensitivity of at
Current edition approved Nov. 10, 1998. Published January 1999. Originally
least 0.1 mg.
published as D 4659 – 87. Last previous edition D 4659 – 93.
Annual Book of ASTM Standards, Vol 08.01.
Annual Book of ASTM Standards, Vol 11.01.
4 5
Annual Book of ASTM Standards, Vol 14.03. Annual Book of ASTM Standards, Vol 15.05.
*A 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.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 4659
6. Reagents and Materials container until it becomes liquid. Rapidly cool the liquid to 22
to 24°C and fill the pycnometer, while minimizing exposure of
6.1 Purity of Reagents—Use reagent grade chemicals in all
the sample to air.
tests. Unless otherwise indicated, it is intended that all reagents
9.5 Insert the thermometer into the pycnometer without
conform to the specifications of the Committee on Analytical
trapping air bubbles. Cover the side arm with the vented cap
Reagents of the American Chemical Society where such
6 and allow the pycnometer to equilibrate in the water bath for at
specifications are available. Other grades may be used, pro-
least 30 min. Wipe the overflow from the side arm capillary
vided it is ascertained that the reagent is of sufficiently high
and cover it with the cap vented. Remove the pycnometer from
purity to permit its use without lessening the accuracy of the
the bath, wipe dry, and weigh. To obtain the weight, S, of the
determination.
sample at 25.0°C, subtract the weight of the empty pycnometer
6.2 Purity of Water—Unless otherwise indicated, references
from the weight when filled with sample.
to water shall be understood to mean reagent water as defined
by Type IV or better of Specification D 1193.
10. Calculation
6.3 Chromic Acid Cleaning Solution—Prepare a saturated
10.1 Calculate the specific gravity at 25/25°C as follows:
solution of chromic acid (CrO ) in concentrated sulfuric acid
S
(H SO , sp gr 1.84).
2 4
Specific gravity, 25/25°C5
W
7. Sampling
where:
7.1 Since organic isocyanates react with atmospheric mois-
S = sample used, g (see 9.5), and
ture, take special precautions in sampling (Warning:
W = water in the pycnometer, g (see 9.3).
Precaution—Note 2). Usual sampling methods (for example,
sampling an open drum with a thief), even when carried out 11. Precision and Bias
rapidly, can cause contamination of the sample with insoluble
11.1 Attempts to develop a precision and bias statement for
urea. Therefore, blanket the sample with dry air or nitrogen at
this test method have not been successful. Data on precision
all times.
and bias cannot be given for this reason. Anyone wishing to
participate in the development of precision and bias data
NOTE 2—Warning: Organic isocyanates are toxic when they are ab-
sorbed through the skin, or when the vapors are breathed. Precaution— should contact the Chairman, Subcommittee D20.22 (Section
Provide adequate ventilation and wear protective gloves and eyeglasses.
D20.22.01), ASTM, 100 Barr Harbor Drive, West Consho-
hocken, PA 19428-2959.
8. Test Conditions
11.2 Test Method E 202 is similar and does include preci-
8.1 Since isocyanates react with moisture, keep laboratory
sion data. Precision statements from E 202 are restated below
humidity low, preferably around 50 % relative humidity.
as an estimate of the precision for this test method.
11.2.1 Repeatability—It has been estimated that duplicate
9. Procedure
results by the same analyst should be considered suspect if they
9.1 Clean the pycnometer by filling it with chromic acid
differ by 0.0002 units.
cleaning solution and by allowing it to stand for a f
...
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