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

ISO 11358-3:2013 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. 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.

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• Status: Withdrawn
• Publication Date: 10-Dec-2013
• Withdrawal Date: 10-Dec-2013
• 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: 9599 - Withdrawal of International Standard
• Completion Date: 29-Jan-2021

Relations

• Revised: 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
• Effective Date: 23-Apr-2020

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 11358-3
First edition
2013-12-15
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 11358-3:2013(E)
©
ISO 2013

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ISO 11358-3:2013(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2013
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ii © ISO 2013 – All rights reserved

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ISO 11358-3:2013(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 . 3
8 Procedure. 3
8.1 General . 3
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 . 5
9.3 Master curves . 6
10 Precision . 9
11 Test report . 9
Annex A (informative) Mathematical background .10
Bibliography .13
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ISO 11358-3:2013(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
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electrotechnical standardization.
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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
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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).
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For an explanation on the meaning of ISO specific terms and expressions related to conformity
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to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 61, Plastics, Subcommittee SC 5, Physical-
chemical properties.
ISO 11358 consists of the following parts, under the general title Plastics — Thermogravimetry (TG) of
polymers:
— Part 1: General principles
— Part 2: Determination of activation energy
— Part 3: Determination of the activation energy using the Ozawa-Friedman plot and the reaction kinetic
analysis
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ISO 11358-3:2013(E)

Introduction
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.
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INTERNATIONAL STANDARD ISO 11358-3:2013(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 International Standard 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.
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.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. 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.
3.1
conversion
Cm=−( mm)/( −m )
ti fi
where
m is the initial quantity, in mg;
i
m is the quantity at a particular time and temperature, in mg;
t
m is the final quantity, in mg.
f
See ISO 11358-1 and ISO 11358-2.
Note 1 to entry: It is also referred to as the mass loss fraction.
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ISO 11358-3:2013(E)

3.2
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.
3.3
generalized rate of conversion
dC/dt
gen
E
dC  dC
a
=exp
 
dt RT dt
 
gen
3.4
master curve
plot that can be used to evaluate the results and investigate the reaction kinetics models
Note 1 to entry: Examples of master curves are 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.
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ISO 11358-3:2013(E)

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 a
...