ASTM D1439-97

Standard Test Methods for Sodium Carboxymethylcellulose

SCOPE
1.1 These test methods cover the testing of sodium carboxymethylcellulose.  
1.2 The test procedures appear in the following order:  Sections Moisture 4 to 9 Degree of Etherification: Test Method A-Acid Wash 10, 11, 12 to 17 Test Method B-Nonaqueous Titration 10, 11, 18 to 23 Viscosity 24 to 30 Purity 31 to 38 Sodium Glycolate 39 to 47 Sodium Chloride 48 to 55 Density 56 to 62
1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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. For specific hazard statements, see Notes 1 and 2.

General Information

• Status: Historical
• Publication Date: 09-Nov-1997
• ICS: 85.040 - Pulps
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.36 - Cellulose and Cellulose Derivatives

Relations

• Replaced By: ASTM D1439-03 - Standard Test Methods for Sodium Carboxymethylcellulose
• Effective Date: 01-Dec-2003

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D1439–97
Standard Test Methods for
Sodium Carboxymethylcellulose
This standard is issued under the fixed designation D 1439; 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 specifications are available. Other grades may be used, pro-
vided it is first ascertained that the reagent is of sufficiently
1.1 These test methods cover the testing of sodium car-
high purity to permit its use without lessening the accuracy of
boxymethylcellulose.
the determination.
1.2 The test procedures appear in the following order:
3.2 Unless otherwise indicated, references to water shall be
Sections
understood to mean distilled water.
Moisture 4-9
Degree of Etherification:
Test Method A—Acid Wash 10-17
MOISTURE
Test Method B—Nonaqueous Titration 10, 11, 18-23
Viscosity 24-30
4. Scope
Purity 31-38
Sodium Glycolate 39-47
4.1 This test method covers the determination of the volatile
Sodium Chloride 48-55
content of sodium carboxymethylcellulose.
Density 56-62
4.2 The results of this test are used for calculating the total
1.3 The values stated in inch-pound units are to be regarded
solids in the sample; and, by common usage, all materials
as the standard. The values given in parentheses are for
volatile at this test temperature are designated as moisture.
information only.
5. Significance and Use
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5.1 Moistureanalysis(alongwithpurity)isusedtocalculate
responsibility of the user of this standard to establish appro-
the amount of active polymer in the material and must be
priate safety and health practices and determine the applica-
consideredwhendeterminingtheamountofsodiumcarboxym-
bility of regulatory limitations prior to use. For specific hazard
ethylcellulose to use in various formulations.
statements, see Note 1 and Note 2.
6. Apparatus
2. Referenced Documents
6.1 Oven—Gravity convection oven, capable of maintain-
2.1 ASTM Standards:
ing a temperature of 105 6 3°C.
D 1347 Test Methods for Methylcellulose
6.2 Weighing Bottles, low-form, 50-mm inside diameter by
E 1 Specification for ASTM Thermometers
30-mm height, or equivalent.
6.3 Analytical Balance.
3. Purity of Reagents
7. Procedure
3.1 Reagent grade chemicals shall be used in all tests.
Unless otherwise indicated, it is intended that all reagents shall
7.1 Weigh3to5gofthe sample to the nearest 0.001 g in a
conform to the specifications of the Committee on Analytical
tared and covered weighing bottle.
Reagents of the American Chemical Society , where such
7.2 Place the bottle in an oven at 105°C for 2 h with the
cover removed. Cool the bottle in a desiccator, replace the
cover, and weigh.
ThesetestmethodsareunderthejurisdictionofASTMCommitteeD-1onPaint
7.3 Replace the sample in the oven for 30 min, cool, and
and Related Coatings, Materials, and Applications and are the direct responsibility
reweigh.
of Subcommittee D01.36 on Cellulose and Cellulose Derivatives.
Current edition approved Nov. 10, 1997. Published July 1998. Originally
7.4 Continue this procedure to a mass loss of not more than
published as D 1439 – 56 T. Last previous edition D 1439 – 94.
5 mg for 30 min drying time.
Annual Book of ASTM Standards, Vol 06.03.
Annual Book of ASTM Standards, Vol 14.03.
4 8. Calculation
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
8.1 Calculate the percent moisture, M, as follows:
listed by the American Chemical Society, see Analar Standards for Laboratory
M 5 ~A/B! 3 100 (1)
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.
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.
D1439
14.4 Hydrochloric Acid, Standard (HCl, 0.3 to 0.5 N).
where:
A 5 mass loss on heating, g, and
14.5 Methanol, anhydrous.
B 5 sample used, g.
14.6 Nitric Acid (sp gr 1.42)—Concentrated nitric acid
(HNO ).
9. Precision and Bias
14.7 Sodium Hydroxide, Standard Solution (0.3 to 0.5 N)—
9.1 Precision—Statistical analysis of interlaboratory repro-
Prepare and standardize a 0.3 to 0.5 N solution of sodium
ducibilitytestresultsonsamplescontaining2to10 %moisture
hydroxide (NaOH).
indicates a precision of 60.2 % absolute at the 95 % confi-
14.8 SulfuricAcid(9 + 2)—Carefullymix9volumesH SO
2 4
dence level.
with 2 volumes of water.
9.2 Bias—No justifiable statement can be made on the bias
of the procedure for measuring moisture because no suitable
15. Procedure
reference material exists.
15.1 Weigh approximately4gofthe sample into a 250-mL
DEGREE OF ETHERIFICATION
beaker and add 75 mLof ethyl alcohol (95 %). Stir the mixture
with an air–driven stirrer until a good slurry is obtained.Add 5
10. Scope
mLof HNO , while agitating, and continue agitation for 1 to 2
10.1 These test methods cover the determination of the
min. Heat the slurry and boil for 5 min. (Warning—See Note
degree of etherification (D.E.) of sodium carboxymethylcellu-
1.) Remove the heat and continue agitation for 10 to 15 min.
lose.
10.2 Two test methods are included as follows:
NOTE 1—Warning: Exercise care to avoid fire.
10.2.1 Test Method A (Acid Wash), for crude grades of
15.2 Decant the supernatant liquid through the filter and
sodium carboxymethylcellulose with degrees of etherification
transfer the precipitate to the filter with 50 to 100 mL of ethyl
up to 0.85. Above 0.85 degree of etherification, slightly low
alcohol (95 %). Wash the precipitate with ethyl alcohol (80 %)
results may be obtained.
that has been heated to 60°C, until all of the acid has been
10.2.2 Test Method B (Nonaqueous Titration), for purified
removed.
grades of sodium carboxymethylcellulose of all degrees of
15.3 Test for the removal of acid and salts (ash) by mixing
etherification. It is not applicable to the crude grades.
Test Method A—Acid Wash a drop of the acid carboxymethylcellulose slurry from the filter
with a drop of diphenylamine reagent on a white spot plate. A
11. Summary of Test Method
bluecolorindicatesthepresenceofnitrateandthenecessityfor
11.1 The water-soluble sodium carboxymethylcellulose is further washing. If the first drop of reagent does not produce a
converted to the insoluble acid form, purified by washing,
blue color, further drops should be added until an excess of
dried, and then a weighed sample is reconverted to the sodium
reagentisknowntobepresent,notingthecoloraftereachdrop.
salt with a measured excess of sodium hydroxide.
Four to six washings will usually suffice to give a negative test
for nitrate.
12. Significance and Use
15.4 Finally, wash the precipitate with a small amount of
12.1 These test methods determine the amount of substitu-
anhydrous methanol and draw air through it until the alcohol is
ent groups added to the cellulose backbone. The level can
completely removed. Transfer the precipitate to a glass or
greatly affect solution properties, rheology, viscosity, hygro-
aluminum weighing dish provided with a cover. Heat the
scopicity, salt tolerance, and many other properties of the
uncovereddishonasteambathuntiltheodorofalcoholcanno
polymer.
longer be detected (in order to avoid fires due to methanol
fumes in the oven), then dry the dish and contents, uncovered
13. Apparatus
for3hat 105°C. Place the cover on the dish and cool to room
13.1 Stirrer, air-driven.
temperature in a desiccator.
13.2 Buchner Funnel, 75-mm, fitted with a 70-mm fine-
15.5 The sulfate ash content of the sample at this point
texture, heavy-duty filter paper. A60-mm medium-porosity,
should be less than 0.5 % when determined on 0.5 g of the
fritted glass funnel may also be used.
sample by the procedure given in theAsh as Sulfate section of
13.3 Drying Oven, maintained at 105°C.
Test Methods D 1347. If the ash content is greater than 0.5 %,
rewash the sample with ethyl alcohol (80 %). If necessary,
14. Reagents
repeat the procedure described in 13.1-13.3 to 13.4.
14.1 Diphenylamine Reagent—Dissolve 0.5 g of dipheny-
15.6 Weigh, to the nearest 0.01 g, about 1 to 1.5 g of the
lamine in 120 mL of sulfuric acid (H SO , 9 + 2). The reagent
2 4
dried acid carboxymethylcellulose (depending on the normal-
should be essentially water-white. It will give a deep blue
ity of the acid and base to be used) into a 500-mL Erlenmeyer
coloration with traces of nitrate or other oxidizing agents.
flask. Add 100 mL of water and 25.00 mL of 0.3 to 0.5 N
14.2 Ethyl Alcohol (95 volume %)—Denatured ethyl alco-
NaOHsolution,whilestirring.Heatthesolution toboiling,and
hol conforming to either Formula 2B, 3A, or 30 of the U. S.
boil for 15 to 30 min.
Bureau of Internal Revenue.
15.7 TitratetheexcessNaOH,whilethesolutionishot,with
14.3 Ethyl Alcohol (80 % by volume)—Dilute 840 mL of
Formula 2B, 3A, or 30 denatured alcohol to 1 L with water. the 0.3 to 0.5 N HCl to a phenolphthalein end point.
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.
D1439
NOTE 2—Warning: The solution of perchloric acid in dioxane should
16. Calculation
never be heated or allowed to evaporate.
16.1 Calculate the degree of etherification, G, as follows:
20.4.1 Standardize the solution as follows: Dry potassium
A 5 ~BC – DE!/F (2)
acid phthalate for2hat 120°C. Weigh 2.5 g to the nearest
G 5 0.162A/~1– 0.0584A! (3)
0.0001 g into a 250-mL volumetric flask. Add glacial acetic
acid, shake to dissolve, and then make up to volume and mix
where:
thoroughly. Pipet 10 mL into a 100-mL beaker and add 50 mL
A 5 milliequivalents of acid consumed per gram of
of acetic acid. Place on a magnetic stirrer and insert the
sample,
electrodes of the pH meter.Add nearly the required amount of
B 5 NaOH solution added, mL,
HClO from a buret, then decrease the increments to 0.05 mL
C 5 normality of the NaOH solution, 4
as the end point is approached. Record the millilitres of titrant
D 5 HCl required for titration of the excess NaOH, mL,
E 5 normality of the HCl, versus millivolts, and continue the titration a few millilitres
F 5 acid carboxymethylcellulose used, g, beyond the end point. Plot the titration curve and read the
162 5 gram molecular mass of the anhydroglucose unit of
volume of titrant at the inflection point. Calculate the normal-
cellulose, and
ity, N, as follows:
58 5 net increase in molecular mass of anhydroglucose
N 5 ~A 3 10 3 1000!/~B 3 204.22 3 250! (4)
unit for each carboxymethyl group substituted.
where:
17. Precision and Bias A 5 potassium acid phthalate used, g,
B 5 HClO added, mL,
17.1 Precision—Statistical analysis of intralaboratory (re-
204.22 5 gram molecular mass of potassium acid phtha-
peatability) test results indicates a precision of 60.04 D.E.
late,
units at the 95 % confidence level.
10 5 potassium acid phthalate solution added, mL,
17.2 Bias—No justifiable statement can be made on the bias
and
oftheprocedureformeasuringdegreeofetherificationbecause
250 5 glacial acetic acid used to dissolve potassium
no suitable reference material exists.
acid phthalate, mL.
Test Method B—Nonaqueous Titration
20.5 Potassium Acid Phthalate, primary standard, National
Institute of Standards and Technology Standard Sample No.
18. Summary of Test Methods
84.
18.1 This measurement is based upon a nonaqueous acid-
base titration. The sample is refluxed with glacial acetic acid, 21. Procedure
and the resulting sodium acetate is titrated with a standard
21.1 Weigh 0.2 g of the sample, to the nearest 0.0001 g, into
solution of perchloric acid in dioxane, to a potentiometric end
a 250-mL Erlenmeyer flask with ground-glass joint. Add 75
point. Impurities containing alkaline sodium will also be
mL of acetic acid, connect to a water-cooled condenser, and
titrated under these conditions. Sodium chloride does not
reflux gently on a hot plate for 2 h.
interfere.
21.2 Cool,andtransferthesolutiontoa250-mLbeakerwith
the aid of 50 mL of acetic acid. Place on the magnetic stirrer
19. Apparatus
and titrate to a potentiometric end point with 0.1 N HClO in
19.1 pHMeter,equippedwithastandardglasselectrodeand
accordance with 20.4.
a calomel electrode modified as follows:
22. Calculation
19.1.1 Discard the aqueous potassium chloride solution,
then rinse and fill with the calomel electrode solution as
22.1 Calculate the degree of etherification, H, as follows
described in 20.2.
(Note 3):
19.1.2 Add a few crystals of potassium chloride and silver
M 5 ~AN 3 100!/~G 3 ~100 2 B!! (5)
chloride or silver oxide to the electrode.
H 5 0.162 M/~1.000– ~0.080 M!! (6)
19.2 Buret, micro, 10-mL capacity.
where:
20. Reagents
M 5 milliequivalents of acid consumed per gram of
20.1 Acetic Acid, glacial. sample,
A 5 HClO added, mL,
20.2 Calomel Electrode Solution—Add2gof potassium
N 5 normality of HClO ,
chloride (KCl) and2gof silver chloride (AgCl) or silver oxide 4
G 5 sample used, g,
(Ag O) to 100 mL of methanol and shake thoroughly to
B 5 percent moisture, determined on a separate sample,
saturate. Use the supernatant liquid.
in accordance with Sections 4-7,
20.3 1,4-Dioxane.
162 5 gram molecular mass of an anhydroglucose unit of
20.4 Perchloric Acid (0.1 N)—Add 9 mL of concentrated
cellulose, and
perchloric acid (HClO , 70 % to 1 L of dioxane, with stirring
80 5 net increase in molecular mass of an anhydroglu-
(Warning—See Note 2). Store in an amber glass bottle. Any
cose unit for each sodium carboxymethyl group
slight discoloration that appears on standing may be disre-
added.
garded.
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.
D1439
NOTE 3—The result calculated in accordance with Section 18 includes
26.2 Container—Glass jar, approximately 2 ⁄2-in. (64-mm)
the alkaline sodium from sodium glycolate; however, if the latter is less
in diameter and 6 in. (152 mm) deep, unconstricted at the top,
than 0.5 %, the interference is negligible.
capacity 12 oz (340 g).
26.3 Analytical Balance.
23. Precision and Bias
26.4 Mechanical Stirrer—Stirrerconstructedofeitherstain-
23.1 Precision—Statistical anal
...