ASTM D3644-98

Standard Test Method for Acid Number of Styrene-Maleic Anhydride Resins

SCOPE
1.1 This test method covers the measurement of the free acidity present in styrene-maleic anhydride resins.  
1.2 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.

General Information

• Status: Historical
• Publication Date: 09-Sep-1998
• ICS: 83.080.10 - Thermosetting materials
• Technical Committee: D21 - Polishes
• Drafting Committee: D21.02 - Raw Materials

Relations

• Replaced By: ASTM D3644-98(2004) - Standard Test Method for Acid Number of Styrene-Maleic Anhydride Resins
• Effective Date: 01-Sep-2004
• Referred By: ASTM D3643-15(2022) - Standard Test Method for Acid Number of Certain Alkali-Soluble Resins
• Effective Date: 10-Sep-1998

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D 3644 – 98
Standard Test Method for
Acid Number of Styrene-Maleic Anhydride Resins
This standard is issued under the fixed designation D 3644; 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 used, provided it is first ascertained that the reagent is of
sufficiently high purity to permit its use without lessening the
1.1 This test method covers the measurement of the free
accuracy of the determination.
acidity present in styrene-maleic anhydride resins.
5.2 Purity of Water—Unless otherwise indicated, references
1.2 This standard does not purport to address all of the
to water shall be understood to mean reagent water conforming
safety concerns, if any, associated with its use. It is the
to Specification D 1193.
responsibility of the user of this standard to establish appro-
5.3 Acetone, conforming to the requirements described in
priate safety and health practices and determine the applica-
Specification D 329.
bility of regulatory limitations prior to use.
5.4 Phenolphthalein Indicator Solution (20 g/L)—Dissolve
2. Referenced Documents 10 g of phenolphthalein in 100 mL of acetone.
5.5 Sodium Hydroxide, Standard Solution (0.1 N)—
2.1 ASTM Standards:
Dissolve7gof sodium hydroxide (NaOH) in 7 mL of water,
D 329 Specification for Acetone
and filter the resulting solution through an asbestos mat in a
D 1193 Specification for Reagent Water
Gooch crucible with the aid of suction. Do not wash the
3. Terminology
residue. Dilute two thirds of the clear filtrate to 1 L with freshly
boiled water. Standardize against National Institute of Stan-
3.1 Definition:
dards and Technology standard sample of acid potassium
3.1.1 acid number—the number of milligrams of potassium
phthalate No. 84, using phenolphthalein as the indicator. Do
hydroxide (KOH) required to neutralize the alkali-reactive
not adjust the concentration of the solution, but calculate the
groups in1gof material under the conditions of test.
normality.
4. Significance and Use
5.6 Sulfuric Acid, Standard Solution (0.1 N)—Measure out
3 mL of concentrated sulfuric acid (H SO )(d 5 1.84) and
4.1 This test method is used to determine the property of
2 4
pour it slowly, and with constant stirring, into about 100 mL of
styrene-maleic anhydride resins functionality. Acid functional-
water. Cool to room temperature, mix thoroughly, and dilute to
ity determines the utility of resin as well as being a significant
1 L. Standardize against 0.1 N NaOH solution, as prepared in
quality control test.
4.5, using phenolphthalein as the indicator. Do not adjust the
5. Reagents and Materials
concentration of the solution, but calculate the normality.
5.1 Purity of Reagents—Reagent grade chemicals shall be
6. Procedure
used in all tests. Unless otherwise indicated, it is intended that
6.1 Weigh 0.1 g of the sample to the nearest 0.0001 g into
all reagents shall conform to the specifications of the Commit-
a 250-mL Erlenmeyer flask.
tee on Analytical Reagents of the American Chemical Society,
6.2 Add 150 6 2 mL of acetone to the flask, stopper it, and
where such specifications are available. Other grades may be
swirl it until the sample is dissolved. All 0.2 mL of phenol-
phthalein indicator solution and titrate with NaOH solution to
This test method is under th
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