ASTM D4669-24

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Designation: D4669 − 18 D4669 − 24
Standard Test Method for
Polyurethane Raw Materials: Determination of Specific
Gravity of Polyols
This standard is issued under the fixed designation D4669; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 These test methods measure the specific gravity of polyols. Test Method A measures the specific gravity of polyols using a
pycnometer and Test Method B lists a reference for measuring the specific gravity of liquids using a density meter that is applicable
to polyols (see Note 1).
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
NOTE 1—There is no known ISO equivalent to this standard.
1.3 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D883 Terminology Relating to Plastics
D4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density Meter
E2251 Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids
E202 Test Methods for Analysis of Ethylene Glycols and Propylene Glycols
3. Terminology
3.1 Definitions—For definitions of terms used in these test methods see Terminology D883.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 specific gravity—the ratio of the weight in air of a given volume of the material at a stated temperature to the weight in air
of an equal volume of water at a stated temperature. It shall be expressed as specific gravity, 25/25°C, indicating that the sample
and reference water were both measured at 25°C.
These test methods are under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.22 on Cellular Materials - Plastics
and Elastomers. It was recommended to ASTM by the Center for the Polyurethane Industry of the American Chemistry Council.
Current edition approved April 1, 2018Feb. 1, 2024. Published April 2018February 2024. Originally approved in 1987. Last previous edition approved in 20132018 as
ɛ1
D4669 – 07D4669 – 18.(2013) . DOI: 10.1520/D4669-18.10.1520/D4669-24.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
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D4669 − 24
4. Significance and Use
4.1 These test methods are suitable for quality control, specification testing, and research. The specific gravity is necessary when
converting kinematic viscosity to absolute viscosity.
TEST METHOD A—SPECIFIC GRAVITY USING A PYCNOMETER
5. Apparatus
5.1 Pycnometer, of 25 or 50-mL capacity, conical shape with a capillary side arm overflow tube complete with a standard-taper
⁄12 ground-glass joint to receive a ground-glass vented cap. A thermometer with a scale graduated from 12 to 38°C in 0.2-degree
divisions joins the neck of the flask with a standard-taper ⁄18 ground-glass joint. The thermometer contained in the pycnometer
shall be calibrated in accordance with Specification E2251.
5.2 Water Bath, capable of maintaining a temperature of 25.0 6 0.05°C during the test.
5.3 Thermometer, an ASTM Low Softening Point Thermometer having a range from -2 to +80°C and conforming to the
requirements for Thermometer S15C as prescribed in Specification E2251.
5.4 Analytical Balance, sensitive to 0.1 mg.
6. Reagents
6.1 Chromic Acid Cleaning Solution—Prepare a saturated solution of chromic acid (CrO ) in concentrated sulfuric acid (H SO ,
3 2 4
sp gr 1.84).
6.2 Acetone, reagent grade
7. Sampling
7.1 High molecular weight polyester and polyether polyols contain molecules covering an appreciable range of molecular weights.
These have a tendency to fractionate during solidification. Unless the material is a finely ground solid it is necessary 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 provide minimum exposure to atmospheric moisture during the sampling.
8. Procedure
8.1 Clean the pycnometer by filling it with a chromic acid cleaning solution. Allow it to stand for a few hours, empty, and rinse
well with distilled water.
8.2 Fill the pycnometer with freshly boiled distilled water cooled to 23 6 1°C, and set the pycnometer thermometer in place
carefully, avoiding trapping of air. Place the pycnometer in the water bath that has been maintained at 25.0 6 0.05°C for at least
30 min and allow it to equilibrate
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