ISO 14897:2023

Plastics — Polyols for use in the production of polyurethanes — Determination of water content

This document specifies methods used to measure the water content of polyols employed as polyurethane raw materials. Method A is a manual amperometric method which has been included to better define the principles of the Karl Fischer measurement. Amperometric methods are applicable to a wide range of polyols, including those which have enough colour to obscure a visual end-point. Method B includes an automated amperometric procedure and an automated coulometric procedure. The coulometric procedure is an absolute method that does not require calibration and gives improved sensitivity compared with amperometric methods.

Plastiques — Polyols destinés à la production de polyuréthanes — Dosage de l'eau

General Information

• Status: Published
• Publication Date: 21-Jun-2023
• ICS: 83.080.10 - Thermosetting materials
• Technical Committee: ISO/TC 61/SC 12 - Thermosetting materials
• Drafting Committee: ISO/TC 61/SC 12 - Thermosetting materials
• Current Stage: 6060 - International Standard published
• Start Date: 22-Jun-2023
• Due Date: 14-Mar-2024
• Completion Date: 22-Jun-2023

Relations

• Revises: ISO 14897:2002 - Plastics — Polyols for use in the production of polyurethane — Determination of water content
• Effective Date: 17-Sep-2022

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 14897
Third edition
2023-06
Plastics — Polyols for use in the
production of polyurethanes —
Determination of water content
Plastiques — Polyols destinés à la production de polyuréthanes —
Dosage de l'eau
Reference number
ISO 14897:2023(E)
© ISO 2023

---------------------- Page: 1 ----------------------
ISO 14897:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
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ISO 14897:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Application .2
6 Interferences . 2
7 Reagents . 3
7.1 Purity of reagents . 3
7.2 Purity of water . 3
7.3 Reagents for Method A (manual titration) . 3
7.4 Reagent for Method B . 3
8 Apparatus . 3
8.1 Apparatus for Method A (manual titration) . 3
8.2 Apparatus for Method B (automated titration) . 4
9 Sampling . 4
10 Standardization of reagent . 5
10.1 Standardization of reagent for Method A (manual titration) . 5
10.2 Standardization of reagent for Method B (automatic amperometric or coulometric
titration) . 5
10.3 Calculation . 6
11 Procedure . 6
11.1 Procedure for Method A (manual titration) . 6
11.2 Procedure for Method B (amperometric or coulometric titration) . 6
12 Expression of results .6
13 Precision and bias .7
13.1 General . 7
13.2 Precision and bias for Method B . 7
13.2.1 Precision . 7
13.2.2 Bias . 8
14 Test report . 8
Annex A (informative) Interlaboratory precision studies . 9
Bibliography .10
iii
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ISO 14897:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent
database available at  www.iso.org/patents. ISO shall not be held responsible for identifying any or all
such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC61, Plastics, Subcommittee SC12,
Thermosetting materials.
This third edition cancels and replaces the second edition (ISO 14897:2002), of which it constitutes a
minor revision.
The changes are as follows:
— the title has been changed to plural form to read: "Plastics — Polyols for use in the production of
polyurethanes — Determination of water content".
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
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ISO 14897:2023(E)
Introduction
This method is for the determination of water content in polyether polyols, which are used in the
preparation of polyurethane prepolymers and polyurethane products. Knowledge of this value is
important to polyurethane production.
The document is based on ASTM D 4672.
v
© ISO 2023 – All rights reserved

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INTERNATIONAL STANDARD ISO 14897:2023(E)
Plastics — Polyols for use in the production of
polyurethanes — Determination of water content
WARNING — Persons using this document should be familiar with normal laboratory practice.
This document does not purport to address all of the safety problems, if any, associated with
its use. It is the responsibility of the user of this document to establish appropriate safety and
health practices and to determine applicable national regulatory conditions prior to use.
1 Scope
This document specifies methods used to measure the water content of polyols employed as
polyurethane raw materials.
Method A is a manual amperometric method which has been included to better define the principles
of the Karl Fischer measurement. Amperometric methods are applicable to a wide range of polyols,
including those which have enough colour to obscure a visual end-point. Method B includes an
automated amperometric procedure and an automated coulometric procedure.
The coulometric procedure is an absolute method that does not require calibration and gives improved
sensitivity compared with amperometric methods.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 6353-1, Reagents for chemical analysis — Part 1: General test methods
ISO 6353-2, Reagents for chemical analysis — Part 2: Specifications — First series
ISO 6353-3, Reagents for chemical analysis — Part 3: Specifications — Second series
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
polyol
organic compound containing two or more hydroxyl groups suitable for reaction with isocyanates
1
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ISO 14897:2023(E)
3.2
polyurethane
polymer prepared by the reaction of an organic di- or polyisocyanate with compounds containing two
or more hydroxyl groups
Note 1 to entry: Polyurethanes may be thermosetting, thermoplastic, rigid or soft and flexible, cellular or non-
cellular.
4 Principle
4.1 Methods A and B are based on amperometric or coulometric titrations with Karl Fischer reagent.
The sulfur dioxide in the reagent first reacts with the alcohol to form an ester which is neutralized by
the base present in the reagent. The anion of the alkyl sulfurous acid is the reactive component. The
titration of water present constitutes the oxidation of the alkyl sulfite to alkyl sulfate by the iodine,
[4]
which consumes the water. The reaction can be formulated as follows :
ROH + SO + R’N → (R’NH)SO R
2 3
H O + I + (R’NH)SO R + 2R’N → (R’NH)SO R + 2(R’NH)I
2 2 3 4
4.2 To determine water, Karl Fischer reagent [a solution of iodine, sulfur dioxide, ethylene glycol
monomethyl ether (HOCH CH OCH ) and pyridine or a pyridine substitute] is added to a solution
2 2 3
of the test portion in methanol or another alcohol until all of the water present has been consumed.
In an amperometric titration, this is evidenced by a current-measuring device that indicates the
depolarization of a pair of platinum electrodes. In coulometric titrations, the iodine reagent is generated
electrically, thus eliminating the need for standardization of the reagent.
5 Application
These test methods are suitable for quality control, as a specification test for products, and for research.
The water content of a polyol is important because water reacts with isocyanates to form carbon
dioxide and an amine which consumes additional isocyanate.
NOTE The description of the manual system presented below is principally for reference purposes and has
been included in order to better define the principles of the Karl Fischer measurement. Commercially available
automated Karl Fischer titrators of the type described in Method B are used extensively. Additional details and
diagrams are available in ISO 760.
6 Interferences
6.1 Oxides, hydroxides and strongly basic compounds react with Karl Fischer reagent, producing an
equivalent amount of water, thus giving falsely high results. Therefore, this method shall not be used
for crude polyols containing KOH or other highly basic products unless corrections are made for the
excess water produced.
6.2 Amine-based polyols can shift the pH of the Karl Fischer syste
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ISO 14897:2023(E) .
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ISO TC 61/SC 12/WG 6
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Plastics — Polyols for use in the production of polyurethanes — Determination of water content
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This document is not an ISO International Standard. It is distributed for review and comment. It is subject to
change without notice and may not be referred to as an International Standard.
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A model manuscript of a draft International Standard (known as “The Rice Model”) is available at
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© ISO 20XX

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ISO /FDIS 14897:2023(E)
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© ISO 2023
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All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of
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this publication may be reproduced or utilized otherwise in any form or by any means, electronic or
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mechanical, including photocopying, or posting on the internet or an intranet, without prior written
permission. Permission can be requested from either ISO at the address below or ISO’sISO's member body in
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the country of the requester.
space between Latin and Asian text, Adjust space
between Asian text and numbers, Border: Left: (No
ISO copyright officeCopyright Office
border), Right: (No border)
CP 401 • Ch. de Blandonnet 8
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CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11 Formatted: Font: 11 pt, Font color: Blue
Email: [e-mail]
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Email: [e-mail]
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Website: www.iso.orgwww.iso.org
Published in Switzerland.
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cm, Adjust space between Latin and Asian text, Adjust
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Kingdom)
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ISO/FDIS 14897:2023(E)
Contents
Foreword . 7
Introduction . 9
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Application . 2
6 Interferences . 2
7 Reagents . 3
7.1 Purity of reagents . 3
7.2 Purity of water . 3
7.3 Reagents for Method A (manual titration) . 3
7.4 Reagent for Method B . 3
8 Apparatus . 4
8.1 Apparatus for Method A (manual titration) . 4
8.2 Apparatus for Method B (automated titration) . 4
9 Sampling . 4
10 Standardization of reagent. 6
10.1 Standardization of reagent for Method A (manual titration) . 6
10.2 Standardization of reagent for Method B (automatic amperometric or coulometric
titration) . 6
10.3 Calculation . 6
11 Procedure . 6
11.1 Procedure for Method A (manual titration) . 6
11.2 Procedure for Method B (amperometric or coulometric titration) . 7
12 Expression of results . 7
13 Precision and bias . 7
13.1 General . 7
13.2 Precision and bias for Method B . 8
13.2.1 Precision . 8
13.2.2 Bias. 8
14 Test report . 8
Annex A (informative) Interlaboratory precision studies . 10

Foreword . iv
Introduction . v
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© ISO 2023 – All rights reserved v

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ISO /FDIS 14897:2023(E)
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1 Scope . 1
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2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Application . 2
6 Interferences . 2
7 Reagents . 3
7.1 Purity of reagents . 3
7.2 Purity of water . 3
7.3 Reagents for Method A (manual titration) . 3
7.4 Reagent for Method B . 3
8 Apparatus . 4
8.1 Apparatus for Method A (manual titration) . 4
8.2 Apparatus for Method B (automated titration) . 4
9 Sampling . 4
10 Standardization of reagent . 6
10.1 Standardization of reagent for Method A (manual titration) . 6
10.2 Standardization of reagent for Method B (automatic amperometric or coulometric
titration) . 6
10.3 Calculation . 6
11 Procedure. 6
11.1 Procedure for Method A (manual titration) . 6
12 Expression of results . 7
13 Precision and bias . 7
13.1 Procedure for Method B (amperometric or coulometric titration) . 7
13.2 General . 8
13.3 Precision and bias for Method B . 8
13.3.1 Precision . 8
13.3.2 Bias . 8
14 Test report . 8
Annex A (informative) Interlaboratory precision studies .10
Bibliography . 1


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6 © ISO 2023 – All rights reserved
vi © ISO 2023 – All rights reserved

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ISO/FDIS 14897:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documentsdocument should be noted. This document was drafted in accordance
with the editorial rules of the ISO/IEC Directives, Part 2 (see
www.iso.org/directiveswww.iso.org/directives).
Attention is drawnISO draws attention to the possibility that some of the elementsimplementation of this
document may beinvolve the subjectuse of (a) patent(s). ISO takes no position concerning the evidence,
validity or applicability of any claimed patent rights. in respect thereof. As of the date of publication of
this document, ISO had not received notice of (a) patent(s) which may be required to implement this
document. However, implementers are cautioned that this may not represent the latest information,
which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held
responsible for identifying any or all such patent rights. Details of any patent rights identified during the
development of the document will be in the Introduction and/or on the ISO list of patent declarations
received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the World
Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.htmlwww.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC61, Plastics, Subcommittee SC12,
Thermosetting materials.
This third edition cancels and replaces the second edition (ISO 14897:2002), of which it constitutes a
minor revision.
The changes are as follows:
— the title has been changed to plural form to read: "Plastics — Polyols for use in the production of
polyurethanes — Determination of water content".
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at
www.iso.org/members.html.www.iso.org/members.html. Formatted: Font: 11 pt
Formatted: Space After: 0 pt, Line spacing: single
© ISO 2023 – All rights reserved 7
© ISO 2023 – All rights reserved vii

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ISO /FDIS 14897:2023(E)
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8 © ISO 2023 – All rights reserved
viii © ISO 2023 – All rights reserved

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ISO/FDIS 14897:2023(E)
Introduction
This method is for the determination of water content in polyether polyols, which are used in the
preparation of polyurethane prepolymers and polyurethane products. Knowledge of this value is
important to polyurethane production.
The standarddocument is based on ASTM D 4672, Standard Test Methods for Polyurethane Raw Materials
— Determination of Water Content of Polyols.


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© ISO 2023 – All rights reserved 9
© ISO 2023 – All rights reserved ix

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Error! Reference source not found. Error! Reference source not found.

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Plastics — Polyols for use in the production of polyurethanes —
between Latin and Asian text, Don't adjust space
Determination of water content
between Asian text and numbers
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WARNING — Persons using this document should be familiar with normal laboratory practice. This document
Formatted: Notice, Don't adjust space between Latin
does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of
and Asian text, Don't adjust space between Asian text
the user of this standarddocument to establish appropriate safety and health practices and to ensure
and numbers
compliance with anydetermine applicable national regulatory conditions prior to use.
Formatted: Don't adjust space between Latin and Asian
text, Don't adjust space between Asian text and
numbers
1 Scope
Formatted: std_publisher, Font:
This document specifies methods used to measure the water content of polyols employed as polyurethane
Formatted: std_docNumber, Font:
raw materials.
Formatted: std_docTitle, Font: Not Italic
Method A is a manual amperometric method which has been included to better define the principles of the
Formatted: RefNorm, Don't adjust space between Latin
Karl Fischer measurement. Amperometric methods are applicable to a wide range of polyols, including those
and Asian text, Don't adjust space between Asian text
which have enough colour to obscure a visual end-point. Method B includes an automated amperometric
and numbers, Tab stops: 0.7 cm, Left + 1.4 cm, Left +
procedure and an automated coulometric procedure.
2.1 cm, Left + 2.8 cm, Left + 3.5 cm, Left + 4.2 cm, Left
+ 4.9 cm, Left + 5.6 cm, Left + 6.3 cm, Left + 7 cm,
The coulometric procedure is an absolute method that does not require calibration and gives improved
Left
sensitivity compared with amperometric methods.
Formatted: std_publisher, Font:
Formatted: std_docNumber, Font:
2 Normative references
Formatted: std_docPartNumber, Font:
The following documents are referred to in the text in such a way that some or all of their content constitutes
Formatted: std_docTitle, Font: Not Italic
requirements of this document. For dated references, only the edition cited applies. For undated references,
Formatted: std_publisher, Font:
the latest edition of the referenced document (including any amendments) applies.
Formatted: std_docNumber, Font:
ISO 3696:1987, Water for analytical laboratory use — Specification and test methods
Formatted: std_docPartNumber, Font:
ISO 6353 -1:1982, Reagents for chemical analysis — Part 1: General test methods
Formatted: std_docTitle, Font: Not Italic
Formatted: std_publisher, Font:
ISO 6353 -2:1983, Reagents for chemical analysis — Part 2: Specifications — First series
Formatted: std_docNumber, Font:
ISO 6353 -3:1987, Reagents for chemical analysis — Part 3: Specifications — Second series
Formatted: std_docPartNumber, Font:
Formatted: std_docTitle, Font: Not Italic
3 Terms and definitions
Formatted
...
Formatted: English (United States)
For the purposes of this document, the following terms and definitions apply.
Formatted: Font: 12 pt, English (United States)
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
Formatted
...
— — ISO Online browsing platform: available at https://www.iso.org/obphttps://www.iso.org/obp
Formatted: English (United States)
— — IEC Electropedia: available at https://www.electropedia.org/https://www.electropedia.org/
Formatted: No underline, Font color: Auto
Formatted: English (United States)
3.1
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...
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ISO /FDIS 14897:2023(E)
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polyol
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an organic compound containing two or more hydroxyl groups suitable for reaction with isocyanates
3.2
polyurethane
a polymer prepared by the reaction of an organic di- or polyisocyanate with compounds containing two or
more hydroxyl groups
NOTENote 1 to entry: Polyurethanes may be thermosetting, thermoplastic, rigid or soft and flexible, cellular or non-
cellular.
4 Principle
4.1 Methods A and B are based on amperometric or coulometric titrations with Karl Fischer reagent. The
sulfur dioxide in the reagent first reacts with the alcohol to form an ester which is neutralized by the base
present in the reagent. The anion of the alkyl sulfurous acid is the reactive component. The titration of water
present constitutes the oxidation of the alkyl sulfite to alkyl sulfate by the iodine, which consumes the water.
1)
[4]
The reaction can be formulated as follows: :
3
ROH ++ SO2 ++ R’N →→ (R’NH)SO R
H2O + I2 + (R’NH)SO3R + 2R’N →→ (R’NH)SO4R + 2(R’NH)I
4.2 To determine water, Karl Fischer reagent [a solution of iodine, sulfur dioxide, ethylene glycol monomethyl
ether (HOCH CH OCH ) and pyridine or a pyridine substitute] is added to a solution of the test portion in
2 2 3
methanol or another alcohol until all of the water present has been consumed. In an amperometric titration,
this is evidenced by a current-measuring device that indicates the depolarization of a pair of platinum
electrodes. In coulometric titrations, the iodine reagent is generated electrically, thus eliminating the need for
standardization of the reagent.
5 Application
These test methods are suitable for quality control, as a specification test for products, and for research. The
water content of a polyol is important because water reacts with isocyanates to form carbon dioxide and an
amine which consumes additional isocyanate.
NOTE The description of the manual system presented below is principally for reference purposes and has been
included in order to better define the principles of the Karl Fischer measurement. Commercially available automated Karl
Fischer titrators of the type described in Method B are used extensively. Additional details and diagrams are available in
ISO 760:1978, Determination of water — Karl Fischer method (General method).
6 Interferences
6.1 Oxides, hydroxides and strongly basic compounds react with Karl Fischer reagent, producing an
equivalent amount of water, thus giving falsely high results. Therefore, this method shall not be used for crude

1)
Scholz, Eugen: Karl Fischer Titration, Springer-Verlag, Berlin, Heidelberg, New York, 1984.
2 Error! Reference source not found.

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ISO/FDIS 14897:2023(E)
polyols containing KOH or other highly basic products unless corrections are made for the excess water
produced.
6.2 Amine-based polyols maycan shift the pH of the Karl Fischer system into the alkaline range, causing
incorrect results. This problem may be circumvented by adding salicylic or benzoic acid in greater than
stoichiometric amounts before carrying out the titration. Tests should be run to determine the suitability of
the procedure for a particular polyol type.
7 Reagents
7.1 Purity of reagents
Reagent-grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents
shall conform to the specifications of ISO 6353-1, ISO 6353-2 and ISO 6353-3. Other grades may be used,
provided that it is first determined that the reagent is of sufficiently high purity to permit its use without
lessening the accuracy of the determination.
7.2 Purity of water
Unless otherwise indicated, references to water shall be understood to mean grade 3 water as defined in
ISO 3696.
7.3 Reagents for Method A (manual titration)
7.3.1 Karl Fischer reagent, equivalent to 2,5 mg to 3,5 mg of water/ml. Dilute commercially available
stabilized Karl Fischer reagent (6 mg of water/ml) with an equal volume of anhydrous ethylene glycol
monomethyl ether (containing less than 0,1 % of water).
NOTE Improved, pyridine-free Karl Fischer reagents have been made available and are highly recommended as a
replacement for the previous reagents.
7.3.2 Titration solvent (anhydrous methanol): Unless the methanol is extremely dry, it will require a
large amount of dilute Karl Fischer reagent to react with its residual water. For this reason, dry the solvent
further by adding undiluted Karl Fischer reagent (6 mg of water/ml) to a bottle of methanol until a light red-
brown colour persists. Then add methanol until the solution is a pale yellow. A 100 ml portion of the treated
solvent should require 1 ml to 10 ml of dilute Karl Fischer reagent.
7.4 Reagent for Method B
7.4.1 Karl Fischer reagent: Commercial reagents and reagent systems of various types are available for
use with autotitrators for water determination. These pyridine-free reagents have improved stability and a
less objectionable odour than the conventional Karl Fischer reagent. Reagents can be purchased in split or
composite forms in different concentrations to fit various ranges of water content. A composite reagent
contains all of the components required for a Karl Fischer titration in a single solution. A split reagent implies
separate solutions of the solvent and titrant.
Error! Reference source not found. 3

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ISO /FDIS 14897:2023(E)
Formatted: Font: 11.5 pt
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Formatted: Font: 11.5 pt
8 Apparatus
Formatted: Font: 11 pt
8.1 Apparatus for Method A (manual titration)
8.1.1 Titration vessel: A vessel of approximately 300 ml capacity, such as a tall-form, lipless beaker
provided with a tight-fitting closure to protect the reaction mixture from atmospheric moisture. The vessel
shall also be fitted with a nitrogen inlet tube, a 10 ml burette, a stirrer (preferably magnetic) and a port that
may be opened momentarily for sample and solvent addition, or removal of electrodes. It is convenient to
provide a vacuum line leading to a 1 litrel trap bottle for drawing off the titrated solution. Pass the nitrogen
through a drying tube containing anhydrous calcium sulfate before it enters the titration vessel.
8.1.2 Instrument electrodes, platinum, with a surface equivalent of two No. 26 wires, 4,76 mm long. The
wires shall be 3 mm to 8 mm apart and inserted in the vessel so that 75 ml of solution will cover them.
8.1.3 Instrument depolarization indicator, having an internal resistance of less than 5 000 Ω, consisting
of a means of applying and indicating a voltage of 20 mV to 50 mV across the electrodes, and capa
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 14897
ISO/TC 61/SC 12
Plastics — Polyols for use in the
Secretariat: JISC
production of polyurethanes —
Voting begins on:
2023-03-31 Determination of water content
Voting terminates on:
2023-05-26
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 14897:2023(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2023

---------------------- Page: 1 ----------------------
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 14897
ISO/TC 61/SC 12
Plastics — Polyols for use in the
Secretariat: JISC
production of polyurethanes —
Voting begins on:
Determination of water content
Voting terminates on:
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
RECIPIENTS OF THIS DRAFT ARE INVITED TO
ISO copyright office
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
CP 401 • Ch. de Blandonnet 8
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
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DOCUMENTATION.
Phone: [phone]
IN ADDITION TO THEIR EVALUATION AS
Reference number
Email: [e-mail]
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 14897:2023(E)
Website: www.iso.org
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
Published in Switzerland
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
ii
  © ISO 2023 – All rights reserved
NATIONAL REGULATIONS. © ISO 2023

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ISO/FDIS 14897:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Application .2
6 Interferences . 2
7 Reagents . 3
7.1 Purity of reagents . 3
7.2 Purity of water . 3
7.3 Reagents for Method A (manual titration) . 3
7.4 Reagent for Method B . 3
8 Apparatus . 3
8.1 Apparatus for Method A (manual titration) . 3
8.2 Apparatus for Method B (automated titration) . 4
9 Sampling . 4
10 Standardization of reagent . 5
10.1 Standardization of reagent for Method A (manual titration) . 5
10.2 Standardization of reagent for Method B (automatic amperometric or coulometric
titration) . 5
10.3 Calculation . 6
11 Procedure . 6
11.1 Procedure for Method A (manual titration) . 6
12 Expression of results .6
13 Precision and bias .7
13.1 Procedure for Method B (amperometric or coulometric titration) . 7
13.2 General . 7
13.3 Precision and bias for Method B . 7
13.3.1 Precision . 7
13.3.2 Bias . 7
14 Test report . 8
Annex A (informative) Interlaboratory precision studies . 9
Bibliography .10
iii
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ISO/FDIS 14897:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non­governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent
database available at  www.iso.org/patents. ISO shall not be held responsible for identifying any or all
such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC61, Plastics, Subcommittee SC12,
Thermosetting materials.
This third edition cancels and replaces the second edition (ISO 14897:2002), of which it constitutes a
minor revision.
The changes are as follows:
— the title has been changed to plural form to read: "Plastics — Polyols for use in the production of
polyurethanes — Determination of water content".
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
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ISO/FDIS 14897:2023(E)
Introduction
This method is for the determination of water content in polyether polyols, which are used in the
preparation of polyurethane prepolymers and polyurethane products. Knowledge of this value is
important to polyurethane production.
The document is based on ASTM D 4672.
v
© ISO 2023 – All rights reserved

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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 14897:2023(E)
Plastics — Polyols for use in the production of
polyurethanes — Determination of water content
WARNING — Persons using this document should be familiar with normal laboratory practice.
This document does not purport to address all of the safety problems, if any, associated with
its use. It is the responsibility of the user of this document to establish appropriate safety and
health practices and to determine applicable national regulatory conditions prior to use.
1 Scope
This document specifies methods used to measure the water content of polyols employed as
polyurethane raw materials.
Method A is a manual amperometric method which has been included to better define the principles
of the Karl Fischer measurement. Amperometric methods are applicable to a wide range of polyols,
including those which have enough colour to obscure a visual end­point. Method B includes an
automated amperometric procedure and an automated coulometric procedure.
The coulometric procedure is an absolute method that does not require calibration and gives improved
sensitivity compared with amperometric methods.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 6353­1, Reagents for chemical analysis — Part 1: General test methods
ISO 6353­2, Reagents for chemical analysis — Part 2: Specifications — First series
ISO 6353­3, Reagents for chemical analysis — Part 3: Specifications — Second series
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
polyol
organic compound containing two or more hydroxyl groups suitable for reaction with isocyanates
1
© ISO 2023 – All rights reserved

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ISO/FDIS 14897:2023(E)
3.2
polyurethane
polymer prepared by the reaction of an organic di- or polyisocyanate with compounds containing two
or more hydroxyl groups
Note 1 to entry: Polyurethanes may be thermosetting, thermoplastic, rigid or soft and flexible, cellular or non-
cellular.
4 Principle
4.1 Methods A and B are based on amperometric or coulometric titrations with Karl Fischer reagent.
The sulfur dioxide in the reagent first reacts with the alcohol to form an ester which is neutralized by
the base present in the reagent. The anion of the alkyl sulfurous acid is the reactive component. The
titration of water present constitutes the oxidation of the alkyl sulfite to alkyl sulfate by the iodine,
[4]
which consumes the water. The reaction can be formulated as follows :
3
ROH + SO + R’N → (R’NH)SO R
2
H O + I + (R’NH)SO R + 2R’N → (R’NH)SO R + 2(R’NH)I
2 2 3 4
4.2 To determine water, Karl Fischer reagent [a solution of iodine, sulfur dioxide, ethylene glycol
monomethyl ether (HOCH CH OCH ) and pyridine or a pyridine substitute] is added to a solution
2 2 3
of the test portion in methanol or another alcohol until all of the water present has been consumed.
In an amperometric titration, this is evidenced by a current-measuring device that indicates the
depolarization of a pair of platinum electrodes. In coulometric titrations, the iodine reagent is generated
electrically, thus eliminating the need for standardization of the reagent.
5 Application
These test methods are suitable for quality control, as a specification test for products, and for research.
The water content of a polyol is important because water reacts with isocyanates to form carbon
dioxide and an amine which consumes additional isocyanate.
NOTE The description of the manual system presented below is principally for reference purposes and has
been included in order to better define the principles
...