ASTM D6869-17

Standard Test Method for Coulometric and Volumetric Determination of Moisture in Plastics Using the Karl Fischer Reaction (the Reaction of Iodine with Water)

SIGNIFICANCE AND USE
4.1 Moisture will affect the process ability of some plastics. High moisture content causes surface imperfections (that is, splay or bubbling) or degradation by hydrolysis. Low moisture (with high temperature) causes polymerization.  
4.2 The physical properties of some plastics are affected by the moisture content.
SCOPE
1.1 This method uses the reaction of Iodine (I2) with water (Karl Fischer Reaction) to determine the amount of moisture in a polymer sample.2  
1.2 This test method is intended to be used for the determination of moisture in most plastics. Plastics containing volatile components such as residual monomers and plasticizers are capable of releasing components that will interfere with the I2/water reaction.  
1.3 This method is suitable for measuring moisture over the range of 0.005 to 100 %. Sample size shall be adjusted to obtain an accurate moisture measurement.  
1.4 The values stated in SI units are regarded as the standard.
Note 1: This standard is equivalent to ISO 15512 Method B.  
1.5 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.  
1.6 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: 30-Nov-2017
• ICS: 83.080.01 - Plastics in general
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.70 - Analytical Methods

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: D6869 − 17
Standard Test Method for
Coulometric and Volumetric Determination of Moisture in
Plastics Using the Karl Fischer Reaction (the Reaction of
1
Iodine with Water)
This standard is issued under the fixed designation D6869; 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.
2
1. Scope* 3. Summary of Test Method
1.1 This method uses the reaction of Iodine (I ) with water 3.1 Samples are heated to vaporize water that is transported
2
(Karl Fischer Reaction) to determine the amount of moisture in by a nitrogen carrier gas to the titration cell. The moisture
2
a polymer sample. collected in the solution within the titration cell is determined
using the reaction of water with I .
2
1.2 This test method is intended to be used for the determi-
nation of moisture in most plastics. Plastics containing volatile 3.2 Endpoint detection is made by instrumented methods.
components such as residual monomers and plasticizers are Determination of the moisture present is made using the
capable of releasing components that will interfere with the reaction of I with water.
2
I /water reaction.
2
3.3 Coulometric instruments use Faraday’s law to measure
1.3 This method is suitable for measuring moisture over the the moisture present with 10.71 Coulombs (C) of generating
- -
range of 0.005 to 100 %. Sample size shall be adjusted to current corresponding to 1 mg of water (2I → I +2e ).
2
obtain an accurate moisture measurement. Volumetric instruments measure the volume of solution con-
taining I that is required to keep the current constant.
2
1.4 The values stated in SI units are regarded as the
standard.
4. Significance and Use
NOTE 1—This standard is equivalent to ISO 15512 Method B.
4.1 Moisture will affect the process ability of some plastics.
1.5 This standard does not purport to address all of the
High moisture content causes surface imperfections (that is,
safety concerns, if any, associated with its use. It is the
splay or bubbling) or degradation by hydrolysis. Low moisture
responsibility of the user of this standard to establish appro-
(with high temperature) causes polymerization.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4.2 The physical properties of some plastics are affected by
1.6 This international standard was developed in accor-
the moisture content.
dance with internationally recognized principles on standard-
5. Interferences
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
5.1 Some compounds, such as aldehydes and ketones,
mendations issued by the World Trade Organization Technical
interfere in the determination of moisture content using this
Barriers to Trade (TBT) Committee.
method.
2. Referenced Documents
6. Apparatus
2.1 ISO Document: 6.1 Heating Unit, consisting of an oven capable of heating
3
ISO 15512 Plastics—Determination of Water Content
the sample to approximately 300°C, a furnace tube, a tempera-
turecontrolunit,acarriergasflowmeter,anddesiccatingtubes
for the carrier gas.
1
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
6.2 SamplePan(Boat),normallyaglasssampleboatorboat
and is the direct responsibility of Subcommittee D20.70 on Analytical Methods.
Current edition approved Dec. 1, 2017. Published January 2018. Originally
manufactured of a suitable material to transfer the oven heat to
approved in 2003. Last previous edition approved in 2011 as D6869 - 03(2011).
the sample. It is permitted to use aluminum foil as a disposable
DOI:10.1520/D6869-17.
2 liner for the sample pan.
See Appendix X1, History of Reagents Associated With the Karl Fischer
Reaction, for an explanation of coulometric and volumetric techniques as well as an
6.3 Titration Unit, consisting of a control unit, titration cell
explanation of the Karl Fischer Reaction and Karl Fischer Reagents.
3
with a solution cathode, platinum electrode, and solution
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. stirring capability.This apparatus has the capability to generate
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D6
...

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: D6869 − 03 (Reapproved 2011) D6869 − 17
Standard Test Method for
Coulometric and Volumetric Determination of Moisture in
Plastics Using the Karl Fischer Reaction (the Reaction of
1
Iodine with Water)
This standard is issued under the fixed designation D6869; 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 Scope*
1.1 This method uses the reaction of Iodine (I ) with water (Karl Fischer Reaction) to determine the amount of moisture in a
2
2
polymer sample.
1.2 This test method is intended to be used for the determination of moisture in most plastics. Plastics containing volatile
components such as residual monomers and plasticizers are capable of releasing components that will interfere with the I /water
2
reaction.
1.3 This method is suitable for measuring moisture over the range of 0.005 to 100 %. Sample size shall be adjusted to obtain
an accurate moisture measurement.
1.4 The values stated in SI units are regarded as the standard.
NOTE 1—This standard is technically equivalent to ISO 15512 Method B.
1.5 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.6 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.
2. Referenced Documents
2.1 ISO Document:
3
ISO 15512 Plastics—Determination of Water Content
2
3. Summary of Test Method
3.1 Samples are heated to vaporize water that is transported by a nitrogen carrier gas to the titration cell. The moisture collected
in the solution within the titration cell is determined using the reaction of water with I .
2
3.2 Endpoint detection is made by instrumented methods. Determination of the moisture present is made using the reaction of
I with water.
2
3.3 Coulometric instruments use Faraday’s law to measure the moisture present with 10.71 Coulombs (C) of generating current
- -
corresponding to 1 mg of water (2I → I + 2e ). Volumetric instruments measure the volume of solution containing I that is
2 2
required to keep the current constant.
4. Significance and Use
4.1 Moisture will affect the processability process ability of some plastics. High moisture content causes surface imperfections
(that is, splay or bubbling) or degradation by hydrolysis. Low moisture (with high temperature) causes polymerization.
1
This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.70 on Analytical Methods.
Current edition approved Sept. 1, 2011Dec. 1, 2017. Published October 2011January 2018. Originally approved in 2003. Last previous edition approved in 20032011 as
D6869 - 03.D6869 - 03 DOI:10.1520/D6869-03R11.(2011). DOI:10.1520/D6869-17.
2
See Appendix X1, History of Reagents Associated With the Karl Fischer Reaction, for an explanation of coulometric and volumetric techniques as well as an explanation
of the Karl Fischer Reaction and Karl Fischer Reagents.
3
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D6869 − 17
4.2 The physical properties of some plastics are affected by the moisture content.
5. Interferences
5.1 Some compounds, such as aldehydes and ketones, interfere in the determination of moisture content using this method.
6. Apparatus
6.1 Heating Unit, consisting of an oven capable of heating the sample to approximately 300°C, a furnace tube, a temperature
control unit, a carrier gas flow meter, and desiccating tubes for the carrier gas.
6.2 Sample Pan (Boat), normally a glass sample boat or boat manufactured of a suitable material to transfer the oven heat to
the
...