ASTM D914-95

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 914 – 95
Standard Test Methods for
Ethylcellulose
This standard is issued under the fixed designation D 914; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope specifications are available. Where such specifications have
not been established, reagents of the best grade available shall
1.1 These test methods cover the testing of ethylcellulose.
be used. References to water shall be understood to mean
1.2 The test procedures appear in the following order:
distilled water.
Sections
Moisture 4 to 6
MOISTURE
Sulfated Ash 7 to 11
Chlorides (as Sodium Chloride) 12 to 16
Ethoxyl Content 20 to 24
4. Scope
Viscosity 25 to 39
4.1 This test method covers the determination of the volatile
1.3 This standard may involve hazardous materials, opera-
content of ethylcellulose.
tions, and equipment. This standard does not purport to
5. Significance and Use
address all of the safety concerns, if any, associated with its
use. It is the responsibility of the user of this standard to
5.1 The results of this test are used for calculating the total
establish appropriate safety and health practices and deter-
solids in the sample and, by common usage, all materials
mine the applicability of regulatory limitations prior to use.
volatile at this test temperature are designated as moisture.
5.2 Moisture analysis (along with sulfated ash) is used to
2. Referenced Documents
calculate the amount of active polymer in the material and shall
2.1 ASTM Standards:
be considered when determining the amount of ethylcellulose
D 362 Specification for Industrial Grade Toluene
in various functions.
D 446 Specifications and Operating Instructions for Glass
6. Apparatus
Capillary Kinematic Viscometers
D 841 Specification for Nitration Grade Toluene
6.1 Oven, gravity convection, capable of maintaining a
D 4794 Test Method for Determination of Ethoxyl or Hy-
temperature of 105 6 3°C.
droxyethoxyl Substitution in Cellulose Ether Products by
6.2 Weighing Bottles.
Gas Chromatography
6.3 Analytical Balance.
E 1 Specification for ASTM Thermometers
7. Procedure
3. Purity of Reagents and Materials
7.1 Weigh accurately 2 to5gofthe sample to the nearest
3.1 Reagent grade chemicals shall be used in all tests.
0.001 g into a tared dish (fitted with a lid) and dry for2hinan
Unless otherwise indicated, all of the reagents used shall
oven at 100 to 105°C. Remove the dish from the oven, cover
conform to the specifications of the Committee on Analytical
with a lid, cool in a desiccator, and weigh.
Reagents of the American Chemical Society, where such
8. Calculation
8.1 Calculate the percent moisture, M as follows:
1 M 5 ~A/B! 3 100 (1)
These test methods are under the jurisdiction of ASTM Committee D-1 on Paint
and Related Coatings, Materials, and Applications, and are the direct responsibility
where:
of Subcommittee D01.36 on Cellulose and Cellulose Derivatives.
A = mass loss on heating, g, and
Current edition approved Sept. 15, 1995. Published November 1995. Originally
e1
published as D 914 – 47 T. Last previous edition D 914 – 72(89) .
Annual Book of ASTM Standards, Vol 06.03.
Annual Book of ASTM Standards, Vol 05.01.
Annual Book of ASTM Standards, Vol 06.04.
Reagent Chemicals, American Chemical Society Specifications, American
Annual Book of ASTM Standards, Vol 14.03.
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. Pharmaceutical Convention, Inc. (USPC), Rockville,
MD.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 914
chloride content of ethylcellulose.
B = sample used, g.
9. Precision and Bias 18. Significance and Use
9.1 Precision—Statistical analysis of intralaboratory (re- 18.1 Sodium chloride is a major by-product of the ethylcel-
lulose manufacturing process. This test is a measure of the
peatability) test results indicates a precision of 65 % at the
95 % confidence level. purity of ethylcellulose. Chlorides may also affect solution
properties.
9.2 Bias—No statement of bias can be made as no suitable
reference material is available as a standard.
19. Apparatus
SULFATED ASH 7
19.1 Titration pH Meter.
19.2 Mercury-Mercurous Sulfate Reference Electrode —
10. Scope
The electrode uses a potassium sulfate electrolyte to avoid
10.1 This test method covers the determination of the
chloride contamination from a chloride electrolyte.
residue on ignition of ethylcellulose after a specimen has been
19.3 Silver-Silver Chloride Electrode —The electrode is
treated with sulfuric acid.
coated with silver chloride periodically. Prepare the electrode
11. Significance and Use
by polishing with fine steel wool, briefly soaking it in 5 %
potassium cyanide solution, and rinsing it with water. Coat the
11.1 This test method (along with moisture) is used to
electrode with silver chloride by electrodeposition from 0.1 N
calculate the active polymer in the material. It shall be used
potassium chloride solution using a 3-V dry cell and a platinum
when testing ethylcellulose in United States government regu-
wire electrode. Connect the silver electrode to the positive pole
lated applications. Excessive ash may also affect solution
of the battery and electrolyze for 20 s; then reverse the
clarity and film properties.
connections for 5 s. Repeat these operations twice, and finally,
12. Apparatus
chloridize the silver electrode for 20 s at the positive terminal.
12.1 Muffle Furnace, maintained at 575 6 25°C.
Store the silver electrode in 0.1 N potassium chloride solution.
12.2 Crucibles, either porcelain, Coors No. 1, or platinum.
Rinse the electrode with water and wipe it with a soft tissue
before each titration.
13. Reagent
19.4 Salt Bridge for Reference Electrode—Fig. 1 shows one
13.1 Sulfuric Acid (sp gr 1.84)—Concentrated sulfuric acid
configuration in use. Exact dimensions are not important. The
(H SO ).
2 4
salt bridge is used to keep the reference electrode from
plugging with the ethylcellulose slurry.
14. Procedure
19.5 Air-Driven Stirrer.
14.1 Ignite a crucible for 10 to 15 min at 800 6 25°C, cool
in a desiccator, and weigh to the nearest 0.001 g.
20. Reagents
14.2 Weigh about5gof sample to the nearest 0.001 g
20.1 Ethanol (95 volume %), undenatured or specially
(previously dried for3hat 105°C) into the crucible. Burn off
denatured conforming to Formula 2B of the U.S. Bureau of
the bulk of the carbonaceous material directly over a flame.
Internal Revenue.
After cooling, add 1 mL of H SO in such a way as to moisten
2 4
20.2 Ethanol-Distilled Water Solvent Mixture (80 + 20)—
the entire ash; then cautiously heat with the burner to dense
Mix 800 g of 2B ethanol with 200 g of water. Add 7.5 g of
white fumes. Ignite in a muffle furnace at 800 6 25°C until all
Aerosol OT 100 % surface-active agent per 3000 g of
signs of carbon are gone. Cool in a desiccator and reweigh to
ethanol-water mixture.
the nearest 0.001 g.
20.3 Potassium Nitrate (KNO ) Solution (saturated) for salt
15. Calculation bridge (Fig. 1).
20.4 Silver Nitrate, Standard Solution (0.02 N)—Dissolve
15.1 Calculate the percent ash (as sulfate), C, as follows:
3.4 g of silver nitrate (AgNO ) in water, dilute to 1 L with
C 5 ~A/B! 3 100 (2)
water in a volumetric flask, and mix. Weigh exactly 0.5845 g of
dry, primary standard sodium chloride (NaCl), dissolve in 25
where:
mL of water, and dilute to 1 L with water in a volumetric flask.
A = ash, g, and
Add 10 mL of H SO (1 + 16) to each aliquot before titrating.
B = sample used, g.
2 4
Titrate aliquots of this solution potentiometrically with the
16. Precision and Bias
AgNO solution. Calculate the normality, N, of the AgNO
3 3
16.1 Precision—Statistical analysis of interlaboratory (re-
solution as follows:
producibility) test results indicates a precision of 610 % at the
95 % confidence level.
MacBeth Model T or Leeds and Northrup pH meters have been found
16.2 Bias—No statement of bias can be made as no suitable
satisfactory for this purpose.
reference material is available as a standard.
Beckman No. 40455 electrode, manufactured by Beckman Instruments, Inc.,
2500 Harbour Blvd., Mail Station E31D, Fullerton, CA 92634, has been found
CHLORIDES (as Sodium Chloride)
satisfactory for this purpose.
Beckman No. 39261 electrode, manufactured by Beckman Instruments, Inc.,
17. Scope
has been found satisfactory for this purpose.
17.1 This test method covers the determination of the Aerosol OT is available from the American Cyanamid Co., Linden, NJ.
D 914
C 5 @~VN 3 0.05845!/W# 3 1 000 000 (4)
where:
V = AgNO solution, mL,
N = normality of AgNO solution,
W = sample used, g, and
0.05845 = milliequivalent mass of NaCl.
23. Precision and Bias
23.1 Precision—Statistical analysis of interlaboratory (re-
producibility) test results indicates a precision of 65 % at the
95 % confidence level.
23.2 Bias—No statement of bias can be made as no suitable
reference material is available as a standard.
ETHOXYL CONTENT
24. Scope
24.1 This test method covers the determination of the
ethoxyl content of ethylcellulose.
24.2 For an alternative method see Test Method D 4794.
25. Significance and Use
1 1 5 3 1 7 1
in. ⁄32 ⁄8 ⁄16 ⁄8 ⁄2 ⁄8 1 ⁄2 3 6
mm 0.8 3.2 7.9 9.5 12.7 22.2 38 76 152
25.1 This test method determines the amount of substituent
groups added to the cellulose backbone. The level can greatly
FIG. 1 Salt Bridge and Reference Electrode for Chloride
affect solution properties, rheology, solubility parameters, and
Determination
film properties.
26. Apparatus
N 5 ~A/B! 3 0.01 (3)
26.1 Distillation Apparatus, as illustrated in Fig. 2, consist-
where:
ing of a boiling flask with a side arm for admission of carbon
A = 0.01 N NaCl solution added, mL, and
dioxide (CO ) or nitrogen, an air condenser with a trap, and a
B = AgNO solution required for the titration, mL.
receiver.
20.5 Sulfuric Acid (1 + 16)—Add 1 volume of concentrated
26.2 Oil Bath, equipped with a heating device, preferably
sulfuric acid (H SO , sp gr 1.84) slowly with stirring into 16
2 4
electrical, so that the bath can be maintained at 145 to 150°C.
volumes of water.
20.6 Toluene, meeting the requirements of Specification
27. Reagents
D 362.
27.1 Bromine Solution—Dissolve 5 mL of bromine in 145
20.7 Toluene-Ethanol Solvent Mixture (90 + 10)—Mix 900
mL of the potassium acetate (KC H O ) solution. Prepare the
2 3 2
g of toluene with 100 g of ethanol.
bromine solution fresh daily in a hood to remove bromine
vapors.
21. Procedure
27.2 Carbon Dioxide—Pass the CO through a bubble
21.1 Weigh accurately 10 g of sample to the nearest 0.001 g
counter and a dry trap, and then through a pressure regulator
(previously dried for2hat100 to 105°C) and transfer to a
consisting of a glass tee whose vertical arm extends almost to
600-mL beaker containing 200 mL of the toluene-ethanol
the bottom of a 10-in. (254-mm) column of water. A screw
solvent mixture. Stir with an air-driven stirrer until solution is
clamp shall be attached to the thin-walled rubber tubing
complete.
connecting the horizontal arm of the tee with the boiling flask.
21.2 Add 200 mL of the ethanol-water mixture and agitate
This arrangement permits regulation of the flow of gas and
for 5 min to form a uniform emulsion. Immerse the electrodes
allows any excess gas to escape. Nitrogen may be used in place
in the emulsion using an air-driven stirrer for mixing. Add 10
of CO .
mL of H SO (1 + 16) and agitate for 3 to 4 min to allow the
2 4
27.3 Formic Acid (90 %).
system to reach equilibrium.
27.4 Gelatin Capsules—Gelatin capsules of a suitable size
21.3 Titrate slowly with the 0.02 N AgNO solution. Make
to hold from 50 to 60 mg of the dried sample will be required.
intermittent additions of 0.1 mL. It is advisable to allow longer ,
12 13
27.5 Hydriodic Acid (sp gr 1.70) —Hydriodic acid (HI)
periods of time between additions of titrant as the end point is
forms with water a constant-boiling mixture (boiling point 126
approached to avoid passing the equivalence point. Run a
blank by the same procedure.
Size 0 gelatin capsules available from Parke, Davis and Co. are satisfactory for
this purpose.
22. Calculation
Hydriodic acid, available from Merck and Co., WBC 220, P.O. Box 2000,
22.1 Calculate parts per million of chlorides as NaCl, C,as
Rahway, NJ 07065, under the designation “For Methoxyl Determination” has been
follows: found satisfactory for ethoxyl determination.
D 914
27.7 Potassium Acetate Solution (100 g/L)—Dissolve 100 g
of anhydrous potassium acetate (KC H O ) crystal in 1 L of a
2 3 2
solution containing 900 mL of glacial acetic acid and 100 mL
of acetic anhydride.
27.8 Potassium Iodide (KI).
27.9 Sodium Acetate Solution (220 g/L)—Dissolve 220 g of
anhydrous sodium acetate in water and dilute to 1 L.
27.10 Sodium Thiosulfate, Standard Solution (0.1 N)—
Dissolve 25 g of sodium thiosulfate (Na S O ·5H O) in 200
2 2 3 2
mL of water and dilute to 1 L. Use freshly boiled and cooled
water. It is preferable to allow the solution to stand for a few
days before standardization. Standardize the solution against
0.1000 N potassium dichromate (K Cr O ) solution prepared
2 2 7
by dissolving exactly 4.9037 g of K Cr O (National Institute
2 2 7
of Standards and Technology Standard Sample No. 136) in
water and diluting to 1 L in a volumetric flask. By means of a
buret, measure accurately 35 to 45 mL of the K Cr O solution
2 2 7
into a 250-mL Erlenmeyer flask. Add2gofKIand 50 mLof
sulfuric acid (H SO , 1 + 9) and allow to stand for about 5 min.
2 4
Titrate the liberated iodine with the Na S O solution, using
2 2 3
starch indicator solution near the end point. At the end point,
the blue color of the starch indicator will be destroyed, leaving
the pale green color of the chromate ion. The normality of the
Na S O , solution should be checked at least once a week.
2 2 3
Calculate the normality, N, of the Na S O solution as follows:
2 2 3
N 5 ~A/B! 3 0.1 (5)
where:
A = 0.1000 N K Cr O solution added, mL, and
2 2 7
FIG. 2 Distillation Apparatus for Ethoxyl Determination
B =Na S O solution required for the titration, mL.
2 2 3
As an alternative procedure, the Na S O solution may be
2 2 3
to 127°C) that contains 57 % HI. The concentra
...