ISO 11358-3:2021

Plastics — Thermogravimetry (TG) of polymers — Part 3: Determination of the activation energy using the Ozawa-Friedman plot and analysis of the reaction kinetics

This document specifies an analysis method for determining the activation energy using the Ozawa-Friedman plot. It also specifies the preparation of master plots for verification of the reaction kinetics determined by thermogravimetry.

Plastiques — Thermogravimétrie (TG) des polymères — Partie 3: Détermination de l'énergie d'activation à l'aide du graphique d'Ozawa-Friedman et analyse cinétique de la réaction

General Information

• Status: Published
• Publication Date: 28-Jan-2021
• ICS: 83.080.01 - Plastics in general
• Technical Committee: ISO/TC 61/SC 5 - Physical-chemical properties
• Drafting Committee: ISO/TC 61/SC 5/WG 8 - Thermal analysis
• Current Stage: 6060 - International Standard published
• Start Date: 29-Jan-2021
• Due Date: 25-Sep-2022
• Completion Date: 29-Jan-2021

Relations

• Revises: ISO 11358-3:2013 - Plastics — Thermogravimetry (TG) of polymers — Part 3: Determination of the activation energy using the Ozawa-Friedman plot and analysis of the reaction kinetics
• Effective Date: 23-Apr-2020

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 11358-3
Second edition
2021-01
Plastics — Thermogravimetry (TG) of
polymers —
Part 3:
Determination of the activation
energy using the Ozawa-Friedman plot
and analysis of the reaction kinetics
Plastiques — Thermogravimétrie (TG) des polymères —
Partie 3: Détermination de l'énergie d'activation à l'aide du
graphique d'Ozawa-Friedman et analyse cinétique de la réaction
Reference number
ISO 11358-3:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 11358-3:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
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 © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 11358-3:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Test specimens. 2
7 Mass and temperature calibration . 2
7.1 Mass calibration . 2
7.2 Temperature calibration . 2
8 Procedure. 2
8.1 General . 2
8.2 Non-oxidative reactions . 4
8.3 Oxidative reactions . 4
9 Expression of results . 4
9.1 Graphical presentation . 4
9.2 Determination of activation energy . 4
9.3 Master curves . 6
10 Precision . 9
11 Test report . 9
Annex A (informative) Mathematical background .10
Bibliography .14
© ISO 2021 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 11358-3:2021(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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. 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 .html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 5, Physical-
chemical properties.
This second edition cancels and replaces the first edition (ISO 11358-3:2013), which has been
technically revised.
The changes compared to the previous edition are as follows:
— the term "conversion" has been deleted;
— a corresponding reference to ISO 11358-2 has been added in Clause 3;
— details of the gas atmosphere in 8.1 and 8.2 have been clarified.
A list of all parts in the ISO 11358 series can be found on the ISO website.
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 © ISO 2021 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 11358-3:2021(E)

Introduction
The Ozawa-Friedman plot (logarithm of the rate of mass loss versus the reciprocal of absolute
temperature at a given mass loss) is a derivative method that can be applied to data obtained by any
mode of temperature change in thermal analysis; e.g. isothermal, constant heating rate, sample-
controlled thermal analysis, temperature jump, and repeated temperature scanning.
If controlled rate thermogravimetry (CRTG) is used to study the decomposition of polymers, the Ozawa-
Friedman method is typically applied to the analysis of data obtained by CRTG and also to that obtained
by the combined use of isothermal thermogravimetry (iso−TG) with conventional linear heating rate
thermogravimetry (LHTG), i.e. using a constant heating rate.
© ISO 2021 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 11358-3:2021(E)
Plastics — Thermogravimetry (TG) of polymers —
Part 3:
Determination of the activation energy using the Ozawa-
Friedman plot and analysis of the reaction kinetics
1 Scope
This document specifies an analysis method for determining the activation energy using the Ozawa-
Friedman plot. It also specifies the preparation of master plots for verification of the reaction kinetics
determined by thermogravimetry.
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 11358-1, Plastics — Thermogravimetry (TG) of polymers — Part 1: General principles
ISO 11358-2, Plastics — Thermogravimetry (TG) of polymers — Part 2: Determination of activation energy
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11358-1, ISO 11358-2 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
generalized time
t
gen
t
E
 
a
t =−exp dt
 
gen
∫
RT
 
0
where
E is the activation energy, expressed in kJ/mol;
a
R is the gas constant, expressed as 8,314 J/(mol K);
T is the absolute temperature, expressed in Kelvin;
t is time, expressed in minutes.
© ISO 2021 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO 11358-3:2021(E)

3.2
generalized rate of conversion
dC/dt
gen
E
dC  dC
a
=exp
 
dt RT dt
 
gen
Note 1 to entry: For the definition of the degree of conversion, refer to ISO 11358-2.
3.3
master curve
plot that can be used to evaluate the results and investigate the reaction kinetics models
EXAMPLE Conversion versus the generalized time, conversion versus the generalized rate of conversion,
generalized time versus the generalized rate of conversion.
4 Principle
Test specimens are heated using any temperature profile and the change in mass is measured as
a function of temperature and time. At a given conversion, the logarithm of the rate of conversion is
plotted versus the reciprocal of the absolute temperature, and the activation energy is calculated from
the slope of the straight line fit to the data thus obtained.
At least two of the master curves enable verification of the reaction kinetics analysis.
5 Apparatus
The apparatus shall be in accordance with ISO 11358-1.
6 Test specimens
Test specimens shall be in the form of powder, pellets, flakes, filaments, or film. The test specimens
shall be prepared by cutting the material, as necessary, to a size appropriate for the apparatus (see
ISO 11358-1).
7 Mass and temperature calibration
7.1 Mass calibration
The procedure of mass calibration is given in ISO 11358-1.
7.2 Temperature calibration
The procedure of temperature calibration is given in ISO 11358-1.
8 Procedure
8.1 General
The determination of the rate of conversion dC/dt is necessary for the analysis in this document. The
rate of conversion versus absolute temperature shall be determined.
See ISO 11358-1 and ISO 11358-2.
Perform tests using either an isothermal run, constant rate heating, sample mass controlled rate
thermal analysis, temperature jump, repeated temperature scanning, or any com
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 11358-3
ISO/TC 61/SC 5
Plastics — Thermogravimetry (TG) of
Secretariat: DIN
polymers —
Voting begins on:
2020-10-30
Part 3:
Voting terminates on:
Determination of the activation
2020-12-25
energy using the Ozawa-Friedman plot
and analysis of the reaction kinetics
Plastiques — Thermogravimétrie (TG) des polymères —
Partie 3: Détermination de l'énergie d'activation à l'aide du
graphique d'Ozawa-Friedman et analyse cinétique de la réaction
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 11358-3:2020(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 2020

---------------------- Page: 1 ----------------------
ISO/FDIS 11358-3:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
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 © ISO 2020 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/FDIS 11358-3:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Test specimens. 2
7 Mass and temperature calibration . 2
7.1 Mass calibration . 2
7.2 Temperature calibration . 2
8 Procedure. 2
8.1 General . 2
8.2 Non-oxidative reactions . 4
8.3 Oxidative reactions . 4
9 Expression of results . 4
9.1 Graphical presentation . 4
9.2 Determination of activation energy . 4
9.3 Master curves . 6
10 Precision . 9
11 Test report . 9
Annex A (informative) Mathematical background .10
Bibliography .14
© ISO 2020 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO/FDIS 11358-3:2020(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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. 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 .html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 5, Physical-
chemical properties.
This second edition cancels and replaces the first edition (ISO 11358-3:2013), which has been
technically revised.
The changes compared to the previous edition are as follows:
— the term "conversion" has been deleted;
— a corresponding reference to ISO 11358-2 has been added in Clause 3;
— details of the gas atmosphere in 8.1 and 8.2 have been clarified.
A list of all parts in the ISO 11358 series can be found on the ISO website.
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 © ISO 2020 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/FDIS 11358-3:2020(E)

Introduction
The Ozawa-Friedman plot (logarithm of the rate of mass loss versus the reciprocal of absolute
temperature at a given mass loss) is a derivative method that can be applied to data obtained by any
mode of temperature change in thermal analysis; e.g. isothermal, constant heating rate, sample-
controlled thermal analysis, temperature jump, and repeated temperature scanning.
Controlled rate thermogravimetry (CRTG) is used to study the decomposition of polymers. The Ozawa-
Friedman method is typically applied to the analysis of data obtained by CRTG and also to that obtained
by the combined use of isothermal thermogravimetry (iso−TG) with conventional linear heating rate
thermogravimetry (LHTG), i.e. using a constant heating rate.
© ISO 2020 – All rights reserved v

---------------------- Page: 5 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 11358-3:2020(E)
Plastics — Thermogravimetry (TG) of polymers —
Part 3:
Determination of the activation energy using the Ozawa-
Friedman plot and analysis of the reaction kinetics
1 Scope
This document specifies an analysis method for determining the activation energy using the Ozawa-
Friedman plot. It also specifies the preparation of master plots for verification of the reaction kinetics
determined by thermogravimetry.
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 11358-1, Plastics — Thermogravimetry (TG) of polymers — Part 1: General principles
ISO 11358-2, Plastics — Thermogravimetry (TG) of polymers — Part 2: Determination of activation energy
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11358-1, ISO 11358-2 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
generalized time
t
gen
t
E
 
a
t =−exp dt
 
gen
∫
RT
 
0
where
E is the activation energy, expressed in kJ/mol;
a
R is the gas constant, expressed as 8,314 J/(mol K);
T is the absolute temperature, expressed in Kelvin;
t is time, expressed in minutes.
© ISO 2020 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO/FDIS 11358-3:2020(E)

3.2
generalized rate of conversion
dC/dt
gen
E
dC  dC
a
=exp
 
dt RT dt
 
gen
Note 1 to entry: For the definition of the degree of conversion, refer to ISO 11358-2.
3.3
master curve
plot that can be used to evaluate the results and investigate the reaction kinetics models
EXAMPLE Conversion versus the generalized time, conversion versus the generalized rate of conversion,
generalized time versus the generalized rate of conversion.
4 Principle
Test specimens are heated using any temperature profile and the change in mass is measured as
a function of temperature and time. At a given conversion, the logarithm of the rate of conversion is
plotted versus the reciprocal of the absolute temperature, and the activation energy is calculated from
the slope of the straight line fit to the data thus obtained.
At least two of the master curves enable verification of the reaction kinetics analysis.
5 Apparatus
The apparatus shall be in accordance with ISO 11358-1.
6 Test specimens
Test specimens shall be in the form of powder, pellets, flakes, filaments, or film. The test specimens
shall be prepared by cutting the material, as necessary, to a size appropriate for the apparatus (see
ISO 11358-1).
7 Mass and temperature calibration
7.1 Mass calibration
The procedure of mass calibration is given in ISO 11358-1.
7.2 Temperature calibration
The procedure of temperature calibration is given in ISO 11358-1.
8 Procedure
8.1 General
The determination of the rate of conversion dC/dt is necessary for the analysis in this document. The
r
...