ASTM D4662-03
(Test Method)Standard Test Methods for Polyurethane Raw Materials: Determination of Acid and Alkalinity Numbers of Polyols
Standard Test Methods for Polyurethane Raw Materials: Determination of Acid and Alkalinity Numbers of Polyols
SIGNIFICANCE AND USE
These test methods are suitable for quality control, as specification tests, and for research. The acid and alkalinity numbers indicate the extent of a reaction with acids. The results are measures of batch-to-batch uniformity and may be used as correction factors in calculating hydroxyl number.
SCOPE
1.1 These test methods measure the acidic and basic constituents in polyols and other materials of high acidity or alkalinity that are soluble in mixtures of toluene and ethyl alcohol. These test methods do not apply to polyethers. (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 and health practices and determine the applicability of regulatory limitations prior to use.
Note 1—There is no equivalent ISO standard.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D 4662–03
Standard Test Methods for
Polyurethane Raw Materials: Determination of Acid and
1
Alkalinity Numbers of Polyols
This standard is issued under the fixed designation D 4662; 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* titration after adding excess hydrochloric acid.The endpoint of
these titrations also can be determined potentiometrically.
1.1 These test methods measure the acidic and basic con-
stituents in polyols and other materials of high acidity or
5. Significance and Use
alkalinity that are soluble in mixtures of toluene and ethyl
5.1 These test methods are suitable for quality control, as
alcohol. These test methods do not apply to polyethers. (See
specification tests, and for research. The acid and alkalinity
Note 1.)
numbersindicatetheextentofareactionwithacids.Theresults
1.2 This standard does not purport to address all of the
are measures of batch-to-batch uniformity and may be used as
safety concerns, if any, associated with its use. It is the
correction factors in calculating hydroxyl number.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
6. Reagents and Materials
bility of regulatory limitations prior to use.
6.1 Purity of Reagents—Use reagent-grade chemicals in all
NOTE 1—There is no equivalent ISO standard.
tests. Unless otherwise indicated, it is intended that all reagents
conform to the specifications of the Committee on Analytical
2. Referenced Documents
Reagents of the American Chemical Society where such
2
3
2.1 ASTM Standards:
specifications are available. Other grades may be used pro-
D 883 Terminology Relating to Plastics
vided it is first ascertained that the reagent is of sufficiently
D 1193 Specification for Reagent Water
high purity to permit its use without lessening the accuracy of
the determination.
3. Terminology
6.2 Purity of Water—Unless otherwise indicated, references
3.1 Definitions—For definitions of terms used in these test
to water shall be understood to mean reagent water as defined
methods see Terminology D 883.
by Type I of Specification D 1193.
3.2 Descriptions of Terms Specific to This Standard:
6.3 Ethyl Alcohol, 95 %.
3.2.1 acid number—the quantity of base, expressed in
6.4 Hydrochloric Acid (0.1 N)—Prepare a 0.1 N solution of
milligrams of potassium hydroxide, that is required to titrate
hydrochloric acid (HCl). Standardization is unnecessary.
acidic constituents present in1gof sample.
6.5 Phenolphthalein Indicator Solution—Dissolve 0.5 g of
3.2.2 alkalinity number—the quantity of base, expressed as
phenolphthalein in 100 mL of a mixture of equal volumes of
milligrams of potassium hydroxide, present in1gof sample.
water and ethyl alcohol. Add a slight excess of 0.1 N NaOH
solution (pink color) and then just neutralize (colorless) with
4. Summary of Test Method
0.1 N HCl.
4.1 The sample is dissolved in a mixture of toluene and
6.6 Potassium Hydroxide, Standard Alcoholic Solution (0.1
ethyl alcohol. The resulting single-phase solution is titrated at
N)—Dissolve 5.61 g of potassium hydroxide (KOH) in 10 mL
room temperature with alcoholic potassium hydroxide solu-
of carbon dioxide-free water and dilute to 1 L with ethyl
tion,totheendpointindicatedbythecolorchangeoftheadded
alcohol. Store the solution in a chemical-resistant dispensing
phenolphthalein. Alkalinity numbers are determined by back-
bottle protected by a guard tube containing soda-lime or
ascarite. Standardize frequently enough to detect changes of
0.0005 N, preferably against pure potassium acid phthalate
1
These test methods are under the jurisdiction of ASTM Committee D20 on
Plastics and are the direct responsibility of Subcommittee D20.22 on Cellular
Plastics.
3
Current edition approved November 1, 2003. Published January 2004. Originally Reagent Chemicals, American Chemical Society Specifications, American
approved in 1987. Last previous edition approved in 1998 as D 4662 - 98. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or listed by the American Chemical Society, see Analar Standards for Laboratory
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Standards volume information, refer to the standard’s Document Summary page on and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
the ASTM website. MD.
*A Summary of Changes section appears at the end of this st
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