ASTM E3007-21

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Designation: E3007 − 15 E3007 − 21
Standard Practice for
Kinetic Values Used to Evaluate Selection and Use of
Kinetic Reference Values in the Study of Decomposition
Reactions by Thermogravimetry
This standard is issued under the fixed designation E3007; 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 It is the purpose of this practice to provide kinetic parameters for reference material(s) to be used for evaluation of
thermogravimetry methods, apparatus, and software where decomposition mass loss and associated temperature are measured. This
practice addresses nth order reactions.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 There is no International Organization of Standards (ISO) equivalent to this standard.
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 safety, health, and healthenvironmental 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.
2. Referenced Documents
2.1 ASTM Standards:
E473 Terminology Relating to Thermal Analysis and Rheology
E1142 Terminology Relating to Thermophysical Properties
E1641 Test Method for Decomposition Kinetics by Thermogravimetry Using the Ozawa/Flynn/Wall Method
E2958 Test Methods for Kinetic Parameters by Factor Jump/Modulated Thermogravimetry
-1 -1
NOTE 1—Test Methods E1641 and E2958 determine the pre-exponential factor Ain units of min . These results shall be converted to units of s for
comparison to values quoted in this practice using:
21 21 21
ln@A, s # 5 ln@A, min #1ln@60 s ⁄ min# 5 ln@A, min #14.094
This practice is under the jurisdiction of ASTM Committee E37 on Thermal Measurements and is the direct responsibility of Subcommittee E37.02 on Standard Reference
Materials.
Current edition approved June 1, 2015July 1, 2021. Published July 2015July 2021. Originally approved in 2015. Last previous edition approved in 2015 as E3007 – 15.
DOI: 10.1520/E3007-15.10.1520/E3007-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
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E3007 − 21
3. Terminology
3.1 Definitions—Specific technical terms used in this practice are defined in Terminologies E473 and E1142, including
Arrhenius equation, derivative, reaction, and thermogravimetric analysis.
3.1.1 decomposition, n—the process by which a substance is broken up into constituent parts, elements or simpler compounds.
3.1.2 kinetics, chemical, n—the study of the dependence of the chemical reaction rate on temperature and time.
4. Summary of Practice
4.1 Kinetics is the measurement and study of the rate of a chemical reaction to the independent parameters of time and
temperature. This relationship is often described using the Arrhenius expression, where:
dα⁄dt 5 A f~α! exp @2E/RT# (1)
and:
α = fraction reacted (dimensionless),
f(α) = some function of α,
f(α) = some function of α,
-1
E = activation energy (J mol ),
-1 -1
R = gas constant (= 8.314 J mol K ),
-1 -1
R = gas constant (=8.314 J mol K ),
T = absolute temperature (K),
t = time (s),
exp = natural logarithm base,
-1
dα/dt = fraction reaction rate (s ),
-1
dα/dt = fraction reaction rate (s ),
-1
A = pre-exponential factor (s ), and
n = reaction order.
4.2 The function f~α! is commonly in the form:
n
f α 5 1 2 α (2)
~ ! ~ !
and is known as an nth order reaction model.
4.3 Eq 1 may be evaluated in either its exponential or logarithmic form:
ln dα/dt 5 ln A 1ln f(α) 2 E⁄RT (3)
@ # @ # @ #
4.4 The study of kinetics involves the determination of values of E, A, and n for a given chemical reaction.
NOTE 2—Activation energy and pre-exponential factor are not independent parameters.
NOTE 3—The descriptions provided in Eq 1-3 are only mathematical models. That is, they represent the fitting of mathematical equations to often “noisy”
experimental data. In practice, no such model will faithfully describe the complete reaction(s) under all conditions for the materials described in this
practice.
4.5 Values for the kinetic parameters are typically in the ranges of:
20,E,350 kJ/mol,
5,ln@A#,50 with A in s , and
0.0,n,2.0
4.6 Some, thermally reactive materials may change with time. For this reason, certified reference materials may not be available
for use in the evaluation of kinetic parameters. For any purchased reference material(s) of high purity from a commercial laboratory
supply house or national metrology institute, the source, storage conditions and storage time of the material(s) shall be reported.
E3007 − 21
4.7 The recommended kinetic values for the thermally reactive materials ide
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