ASTM D1926-00

Standard Test Methods for Carboxyl Content of Cellulose

SCOPE
1.1 These test methods cover the determination of the carboxyl content, or ion-exchange capacity, of cellulose from any source. Two test methods are described, the sodium chloride-sodium bicarbonate method (1) and the methylene blue method (2). The test methods must be used within their limitations, and it must be recognized that there is no way of determining the accuracy of any method for the determination of carboxyl. The precision of the sodium chloride-sodium bicarbonate method is low in the lower range of carboxyl values. The methylene blue method can be used over the whole range of carboxyl values; it is especially useful in the low range. It is not applicable to the determination of carboxyl in soluble carbohydrate material. Although these test methods may be used to determine the ion-exchange capacity of unbleached pulps, the residual lignin will cause an undetermined error, especially the sulfonic acid groups in unbleached sulfite pulps (3).  
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.

General Information

• Status: Historical
• Publication Date: 09-Nov-2000
• ICS: 85.040 - Pulps
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.36 - Cellulose and Cellulose Derivatives

Relations

• Replaces: ASTM D1926-95 - Standard Test Methods for Carboxyl Content of Cellulose
• Effective Date: 10-Nov-2000
• Replaced By: ASTM D1926-00(2006) - Standard Test Methods for Carboxyl Content of Cellulose
• Effective Date: 01-Apr-2006

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D1926–00
Standard Test Methods for
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Carboxyl Content of Cellulose
This standard is issued under the fixed designation D 1926; 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 4. Purity of Reagents
1.1 These test methods cover the determination of the 4.1 Reagent-grade chemicals shall be used in all tests.
carboxyl content, or ion-exchange capacity, of cellulose from Unless otherwise indicated, it is intended that all reagents shall
any source. Two test methods are described, the sodium conform to the specifications of the Committee on Analytical
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chloride-sodium bicarbonate method (1) and the methylene Reagents of the American Chemical Society, where such
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blue method (2). The test methods must be used within their specifications are available. Other grades may be used, pro-
limitations, and it must be recognized that there is no way of vided it is first ascertained that the reagent is of sufficiently
determining the accuracy of any method for the determination high purity to permit its use without lessening the accuracy of
of carboxyl. The precision of the sodium chloride-sodium the determination.
bicarbonate method is low in the lower range of carboxyl 4.2 Unless otherwise indicated, references to water shall be
values.Themethylenebluemethodcanbeusedoverthewhole understood to mean reagent water conforming to Specification
range of carboxyl values; it is especially useful in the low D 1193.
range. It is not applicable to the determination of carboxyl in
SODIUM CHLORIDE-SODIUM BICARBONATE
soluble carbohydrate material. Although these test methods
METHOD
may be used to determine the ion-exchange capacity of
unbleached pulps, the residual lignin will cause an undeter-
5. Summary of Test Method
mined error, especially the sulfonic acid groups in unbleached
5.1 In the sodium chloride-sodium bicarbonate method the
sulfite pulps (3).
specimen is deashed with hydrochloric acid, washed, soaked in
1.2 This standard does not purport to address all of the
sodium chloride-sodium bicarbonate solution, filtered, and an
safety concerns, if any, associated with its use. It is the
aliquot of the filtrate titrated with 0.01 N hydrochloric acid to
responsibility of the user of this standard to establish appro-
a methyl red end point. The difference between the concentra-
priate safety and health practices and determine the applica-
tion of the filtrate and of the sodium chloride-sodium bicar-
bility of regulatory limitations prior to use.
bonate solution is a measure of the ion-exchange capacity of
the cellulose.
2. Referenced Documents
2.1 ASTM Standards:
6. Reagents
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D 1193 Specification for Reagent Water
6.1 Hydrochloric Acid, Standard (0.01 N)—Prepare and
3. Significance and Use standardize a 0.01 N solution of hydrochloric acid (HCl).
6.2 Hydrochloric Acid (1 + 99)—Dilute 1 volume of con-
3.1 These test methods measure the amount of carboxyl
centrated HCl (sp gr 1.19) with 99 volumes of water.
groups present in wood or cotton linter pulp. Carboxyl groups
6.3 Methyl Red Indicator Solution.
are indicative of the surface charge of the pulp which is a very
6.4 Sodium Chloride-Sodium Bicarbonate Solution—
important quantity for use in the papermaking industry.
Dissolve 5.85 g of sodium chloride (NaCl) and 0.84 g of
sodium bicarbonate (NaHCO ) in water and dilute to 1 L.
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1
These test methods are under the jurisdiction of ASTM Committee D01 on
Paint and Related Coatings, Materials, and Applications and are the direct
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responsibility of Subcommittee D01.36 on Cellulose and Cellulose Derivatives. Reagent Chemicals, American Chemical Society Specifications, American
Current edition approved Nov. 10, 2000. Published January 2001. Originally Chemical Society, Washington, DC. For suggestions on the testing of reagents not
published as D 1926 – 61. Last previous edition D 1926 – 95. listed by the American Chemical Society, see Analar Standards for Laboratory
2
The boldface numbers in parentheses refer to the list of references at the end of Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
these test methods. and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
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Annual Book of ASTM Standards, Vol 11.01. MD.
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D1926–00
6.5 Sodium Hydroxide Solution(0.4g/L)—Dissolve0.4gof materials and various test methods gave percent coefficient of
sodium hydroxide (NaOH) in water and dilute to 1 L. va
...