ASTM E1877-00

Standard Practice for Calculating Thermal Endurance of Materials from Thermogravimetric Decomposition Data

SCOPE
1.1 This practice covers additional treatment of the Arrhenius activation energy data determined by Test Method E 1641 to develop a thermal endurance curve and derive a relative thermal index for materials.  
1.2 This practice is generally applicable to materials with a well-defined decomposition profile, namely a smooth, continuous mass change with a single maximum rate.  
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Mar-2000
• ICS: 71.040.40 - Chemical analysis
• Technical Committee: E37 - Thermal Measurements
• Drafting Committee: E37.10 - Fundamental, Statistical and Mechanical Properties

Relations

• Replaced By: ASTM E1877-00(2005) - Standard Practice for Calculating Thermal Endurance of Materials from Thermogravimetric Decomposition Data
• Effective Date: 01-Mar-2005

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:E1877–00
Standard Practice for
Calculating Thermal Endurance of Materials from
1
Thermogravimetric Decomposition Data
This standard is issued under the fixed designation E 1877; 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 (ε) indicates an editorial change since the last revision or reapproval.
1. Scope defined period of time. In the absence of comparison data for
a control material, a time-to-failure of 60 000 h has been
1.1 This practice covers additional treatment of the Arrhe-
arbitrarilyselectedformeasuringRTI.TheRTIistherefore,the
nius activation energy data determined by Test Method E 1641
failure temperature, T, obtained from the thermal endurance
to develop a thermal endurance curve and derive a relative f
curve.
thermal index for materials.
1.2 This practice is generally applicable to materials with a
4. Summary of Practice
well-defined decomposition profile, namely a smooth, continu-
4.1 The Arrhenius activation energy obtained from Test
ous mass change with a single maximum rate.
Method E 1641 is used to construct the thermal endurance
1.3 There is no ISO standard equivalent to this practice.
curve of a material from which an estimate of lifetime at
1.4 This standard does not purport to address all of the
certain temperatures may be obtained.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5. Significance and Use
priate safety and health practices and determine the applica-
5.1 Thermogravimetry provides a rapid method for the
bility of regulatory limitations prior to use.
determination of the temperature-decomposition profile of a
material.
2. Referenced Documents
5.2 This practice is useful for quality control, specification
2.1 ASTM Standards:
acceptance and research.
2
E 473 Terminology Relating to Thermal Analysis
5.3 This practice shall not be used for product lifetime
E 1142 Terminology Relating to Thermophysical Proper-
predications unless a correlation between test results and actual
2
ties
lifetime has been demonstrated. In many cases, multiple
E 1641 Test Method for Decomposition Kinetics by Ther-
mechanisms occur during the decomposition of a material,
2
mogravimetry
with one mechanism dominating over one temperature range,
3. Terminology and a different mechanism dominating in a different tempera-
ture range. Users of this practice are cautioned to demonstrate
3.1 Definitions of Terms Specific to This Standard:
for their system that any temperature extrapolations are tech-
3.1.1 failure, n—change in some chemical, physical, me-
nically sound.
chanical, electrical or other property of sufficient magnitude to
make it unsuitable for a particular use.
6. Calculation
3.1.2 failure temperature (T ), n—the temperature at which
f
6.1 The following values obtained by Test Method E 1641
a material fails after a selected time.
are used to calculate thermal endurance, estimated thermal life
3.1.3 relative thermal index (RTI), n—a measure of the
and failure temperature.
thermal endurance of a material when compared with that of a
6.1.1 The following definitions apply to 6.1 and 6.3:
controlwithproventhermalendurancecharacteristics.TheRTI
6.1.1.1 E 5 Arrhenius activation energy (J/mol),
is also considered to be the maximum temperature below
6.1.1.2 R 5 Universal gas constant (5 8.314 510 J/(mol
which the material resists changes in its properties over a
K)),
6.1.1.3 β 5 Heating rate (K/min),
1
This practice is under the jurisdiction of Committee E–37 on Thermal 6.1.1.4 β` 5 Heating rate nearest the mid-point of the
Measurements and is the direct responsibility of Subcommittee E37.01 on Test
experimental heating rates (K/min),
Methods.
6.1.1.5 a 5 Approximation integral taken from Table 1,
Current edition approved March 10, 2000. Published May 2000. Originally
6.1.1.6 α 5 Constant conversion value,
published as E 1877 – 97. Last previous edition E 1877 – 97.
2
Annual Book of ASTM Standards, Vol 14.02.
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1

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E1877
TABLE 1 Numerical Integration Constants
log t 5 E / ~2.303RT ! 1 log @E /~R b!# – a (1)
f f
E/RT a
T 5 E / 2.303 R log t – log E / R b 1 a (2)
~ @ $ ~ ! #!
f f
8 5.3699
6.2.1 To calculate t, select the value for the temperature at
f
9 5.8980
the constant conversion point (T ) for a heating rate (β) nearest
10 6.4157
c
11 6.9276
the mid-point of the experimental heating rates. Use this value,
12 7.4327
along with theArrhenius activation energy (E) to calculate the
13 7.9323
, ,
4 5 6
14 8.4273 quantity E/
...