ASTM D3644-15

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

SIGNIFICANCE AND USE
4.1 This test method is used to determine the property of styrene-maleic anhydride resins functionality. Acid functionality determines the utility of resin as well as being a significant quality control test.  
4.2 Because some of the anhydride functionality has been hydrolyzed in the manufacturing process, direct titration with base will produce erroneous data on the total acid content of the fully hydrolyzed resin in use. This test method charges excess alkali to hydrolize the anhydride functionality and neutralize the resulting acid. The remaining unreacted alkali is then back titrated with a standardized acid solution and the acid content is determined by difference.
SCOPE
1.1 This test method covers the measurement of the free acidity present in styrene-maleic anhydride resins.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 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.

General Information

• Status: Historical
• Publication Date: 30-Sep-2015
• ICS: 83.080.10 - Thermosetting materials
• Technical Committee: D21 - Polishes
• Drafting Committee: D21.02 - Raw Materials

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D3644 − 15
Standard Test Method for
1
Acid Number of Styrene-Maleic Anhydride Resins
This standard is issued under the fixed designation D3644; 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 thenbacktitratedwithastandardizedacidsolutionandtheacid
content is determined by difference.
1.1 This test method covers the measurement of the free
acidity present in styrene-maleic anhydride resins.
5. Reagents and Materials
1.2 The values stated in SI units are to be regarded as
5.1 Purity of Reagents—Reagent grade chemicals shall be
standard. No other units of measurement are included in this
used in all tests. Unless otherwise indicated, it is intended that
standard.
all reagents shall conform to the specifications of the Commit-
1.3 This standard does not purport to address all of the
tee onAnalytical Reagents of theAmerican Chemical Society,
safety concerns, if any, associated with its use. It is the
3
where such specifications are available. Other grades may be
responsibility of the user of this standard to establish appro-
used, provided it is first ascertained that the reagent is of
priate safety and health practices and determine the applica-
sufficiently high purity to permit its use without lessening the
bility of regulatory limitations prior to use.
accuracy of the determination.
2. Referenced Documents 5.2 Purity of Water—Unless otherwise indicated, references
2 to water shall be understood to mean reagent water conforming
2.1 ASTM Standards:
to Specification D1193.
D329 Specification for Acetone
D1193 Specification for Reagent Water 5.3 Acetone, conforming to the requirements described in
Specification D329.
3. Terminology
5.4 Phenolphthalein Indicator Solution (20 g/L)—Dissolve
3.1 Definitions:
10 g of phenolphthalein in 100 mL of acetone.
3.1.1 acid number—the number of milligrams of potassium
5.5 Sodium Hydroxide, Standard Solution (0.1 N)—
hydroxide (KOH) required to neutralize the alkali-reactive
Dissolve7gof sodium hydroxide (NaOH) in 7 mL of water,
groups in1gof material under the conditions of test.
and filter the resulting solution through a glass mat in a Gooch
crucible with the aid of suction. Do not wash the residue.
4. Significance and Use
Dilute two thirds of the clear filtrate to 1 L with freshly boiled
4.1 This test method is used to determine the property of
water. Standardize against National Institute of Standards and
styrene-maleic anhydride resins functionality.Acid functional-
Technology standard sample of acid potassium phthalate No.
ity determines the utility of resin as well as being a significant
84, using phenolphthalein as the indicator. Do not adjust the
quality control test.
concentration of the solution, but calculate the normality.
4.2 Because some of the anhydride functionality has been
5.6 Sulfuric Acid, Standard Solution (0.1 N)—Measure out
hydrolyzed in the manufacturing process, direct titration with
3mLofconcentratedsulfuricacid(H SO )(d = 1.84)andpour
2 4
base will produce erroneous data on the total acid content of
it slowly, and with constant stirring, into about 100 mL of
the fully hydrolyzed resin in use. This test method charges
water. Cool to room temperature, mix thoroughly, and dilute to
excess alkali to hydrolize the anhydride functionality and
1 L. Standardize against 0.1 N NaOH solution, as prepared in
neutralize the resulting acid. The remaining unreacted alkali is
4.5, using phenolphthalein as the indicator. Do not adjust the
concentration of the solution, but calculate the normality.
1
ThistestmethodisunderthejurisdictionofASTMCommitteeD21onPolishes
and is the direct responsibility of Subcommittee D21.02 on Raw Materials.
Current edition approved Oct. 1, 2015. Published October 2015. Originally
3
approved in 1983. Last previous edition approved in 2012 as D3644 – 06(2012). Reagent Chemicals, American Chemical Society Specifications, American
DOI: 10.1520/D3644-15. 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 [e-mail]. 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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3644 − 06 (Reapproved 2012) D3644 − 15
Standard Test Method for
1
Acid Number of Styrene-Maleic Anhydride Resins
This standard is issued under the fixed designation D3644; 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 This test method covers the measurement of the free acidity present in styrene-maleic anhydride resins.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D329 Specification for Acetone
D1193 Specification for Reagent Water
3. Terminology
3.1 Definitions:
3.1.1 acid number—the number of milligrams of potassium hydroxide (KOH) required to neutralize the alkali-reactive groups
in 1 g of material under the conditions of test.
4. Significance and Use
4.1 This test method is used to determine the property of styrene-maleic anhydride resins functionality. Acid functionality
determines the utility of resin as well as being a significant quality control test.
4.2 Because some of the anhydride functionality has been hydrolyzed in the manufacturing process, direct titration with base
will produce erroneous data on the total acid content of the fully hydrolyzed resin in use. This test method charges excess alkali
to hydrolize the anhydride functionality and neutralize the resulting acid. The remaining unreacted alkali is then back titrated with
a standardized acid solution and the acid content is determined by difference.
5. Reagents and Materials
5.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where
3
such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high
purity to permit its use without lessening the accuracy of the determination.
5.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water conforming to
Specification D1193.
5.3 Acetone, conforming to the requirements described in Specification D329.
5.4 Phenolphthalein Indicator Solution (20 g/L)—Dissolve 10 g of phenolphthalein in 100 mL of acetone.
1
This test method is under the jurisdiction of ASTM Committee D21 on Polishes and is the direct responsibility of Subcommittee D21.02 on Raw Materials.
Current edition approved Oct. 1, 2012Oct. 1, 2015. Published October 2012October 2015. Originally approved in 1983. Last previous edition approved in 20062012 as
D3644 – 06.D3644 – 06(2012). DOI: 10.1520/D3644-06R12.10.1520/D3644-15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by
the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D3644 − 15
5.5 Sodium Hydroxide, Standard Solution (0.1 N)—Dissolve 7 g of sodium hydroxide (NaOH) in 7 mL of water, and filter the
resulting solution through a glass mat in a Gooch crucible with the aid of suction. Do not wash the residue. Dilute two thirds of
the clear filtrate to 1 L with freshly boiled water. Standardize against National Institute of Standards and Technology standard
sample of acid potassium phthalate No. 84, using phenolphthalein as the indicator. Do not adjust the concentration of the sol
...