ASTM D6188-17(2022)

Standard Test Method for Viscosity of Cellulose by Cuprammonium Ball Fall

SIGNIFICANCE AND USE
5.1 This test method is suitable for use as a rapid control test for pulp manufacture or for careful determination of the viscometric molecular weight of purified cotton or wood derived pulps.  
5.2 This test method is applicable over a very large range of cellulose molecular weights because seven sample sizes are defined. (Sample weights are reduced as cellulose molecular weight increases.)  
5.3 Cotton and high molecular weight pulps may be difficult to dissolve. (Warning—This test method is only valid if the sample dissolves completely without gels.)
SCOPE
1.1 This test method describes the procedure for estimating the molecular weight of cellulose by determining the viscosity of cuprammonium (CuAm) solutions of cellulosic materials, such as wood pulp, cotton, and cotton linters. This test method is suitable for rapid, routine testing of large numbers of samples with high accuracy and precision. This test method updates and extends the procedure reported by the American Chemical Society (ACS).2  
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-May-2022
• ICS: 85.040 - Pulps
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.36 - Cellulose and Cellulose Derivatives

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6188 − 17 (Reapproved 2022)
Standard Test Method for
1
Viscosity of Cellulose by Cuprammonium Ball Fall
This standard is issued under the fixed designation D6188; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
3.1 This standard terminology of cellulose and cellulose
1.1 This test method describes the procedure for estimating
derivatives, see Terminology D1695.
the molecular weight of cellulose by determining the viscosity
of cuprammonium (CuAm) solutions of cellulosic materials,
4. Summary of Test Method
such as wood pulp, cotton, and cotton linters.This test method
is suitable for rapid, routine testing of large numbers of
4.1 An in-process or finished product sample is taken. All
samples with high accuracy and precision. This test method cooking and bleaching chemicals must be washed out of
updates and extends the procedure reported by the American in-process samples. Dry samples are wetted with demineral-
2
Chemical Society (ACS). ized water. Samples are either squeezed or pressed to 20 to
40% consistency as necessary, then passed through a picker.
1.2 The values stated in SI units are to be regarded as the
4.2 The wet pulp sample is dried with air whose maximum
standard. The values given in parentheses are for information
temperatureis120°Candweighedunderconditionsthatcause
only.
the specified quantity of sample to be obtained. The weighed
1.3 This standard does not purport to address all of the
sample is placed in a glass 120-mL(4-oz) bottle, steel shot are
safety concerns, if any, associated with its use. It is the
added, a vacuum is pulled on the bottle, and 97 mL of
responsibility of the user of this standard to establish appro-
cuprammonium solution are added to the bottle. The bottle is
priate safety, health, and environmental practices and deter-
placed on a shaker to mix and dissolve the pulp sample in the
mine the applicability of regulatory limitations prior to use.
CuAm solution.
1.4 This international standard was developed in accor-
4.3 The dissolved sample is transferred to a glass viscosity
dance with internationally recognized principles on standard-
tube. The tube is mounted vertically with a bright light behind
ization established in the Decision on Principles for the
the tube. A special glass bead (see 7.13) is dropped into the
Development of International Standards, Guides and Recom-
center of the solution in the tube. The time is measured in
mendations issued by the World Trade Organization Technical
seconds(s)fortheglassbeadtopassbetweentwomarksonthe
Barriers to Trade (TBT) Committee.
tubewhichare20cmapart.Thistime(s)istheuncorrected“as
is” cuprammonium ball fall viscosity. The temperature of the
2. Referenced Documents
solution is determined, and the correction factor for this
3
temperature is multiplied by the uncorrected viscosity of the
2.1 ASTM Standards:
sample. This gives the “as is” cuprammonium ball fall viscos-
D1193Specification for Reagent Water
ity value.
D1695Terminology of Cellulose and Cellulose Derivatives
E438Specification for Glasses in Laboratory Apparatus
4.4 The “as is” viscosity value for the sample size used is
converted to the 2.50-g ACS viscosity by the equations
provided in 14.4. The viscosity is reported in “ACS seconds.”
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint
5. Significance and Use
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.36 on Cellulose and Cellulose Derivatives.
5.1 Thistestmethodissuitableforuseasarapidcontroltest
CurrenteditionapprovedJune1,2022.PublishedJuly2022.Originallyapproved
for pulp manufacture or for careful determination of the
in 1997. Last previous edition approved in 2017 as D6188–17. DOI: 10.1520/
D6188-17R22.
viscometric molecular weight of purified cotton or wood
2
Carver et al., “A Standard Method for Determining the Viscosity of Cellulose
derived pulps.
in Cuprammonium Hydroxide,” Industrial and Engineering Chemistry, Analytical
Edition, Vol 1, No 1, 1929, pp. 49-51.
5.2 Thistestmethodisapplicableoveraverylargerangeof
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
cellulose molecular weights because seven sample sizes are
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
defined. (Sample weights are reduced as cellulose molecular
Standards volume information, refer to the standard’s Document
...