Standard Test Method for Heat of Reaction of Thermally Reactive Materials by Differential Scanning Calorimetry

SIGNIFICANCE AND USE
5.1 This method is useful in determining the extrapolated onset temperature, the peak heat flow temperature and the heat of reaction of a material. Any onset temperature determined by this method is not valid for use as the sole information used for determination of storage or processing conditions.  
5.2 This test method is useful in determining the fraction of a reaction that has been completed in a sample prior to testing. This fraction of reaction that has been completed can be a measure of the degree of cure of a thermally reactive polymer or can be a measure of decomposition of a thermally reactive material upon aging.  
5.3 The heat of reaction values may be used in Practice E1231 to determine hazard potential figures-of-merit Explosion Potential and Shock Sensitivity.  
5.4 This test method may be used in research, process control, quality assurance, and specification acceptance.
SCOPE
1.1 This test method determines the exothermic heat of reaction of thermally reactive chemicals or chemical mixtures, using milligram specimen sizes, by differential scanning calorimetry. Such reactive materials may include thermally unstable or thermoset materials.  
1.2 This test method also determines the extrapolated onset temperature and peak heat flow temperature for the exothermic reaction.  
1.3 This test method may be performed on solids, liquids or slurries.  
1.4 The applicable temperature range of this method is 25 to 600°C.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.6 There is no ISO method equivalent to this standard.  
1.7 This standard is related to Test Method E537 and to NAS 1613, but provides additional information.  
1.8 This standard may involve hazardous materials, operations, and equipment. 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.

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Publication Date
31-Aug-2012
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ASTM E2160-04(2012) - Standard Test Method for Heat of Reaction of Thermally Reactive Materials by Differential Scanning Calorimetry
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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: E2160 − 04 (Reapproved 2012)
Standard Test Method for
Heat of Reaction of Thermally Reactive Materials by
Differential Scanning Calorimetry
This standard is issued under the fixed designation E2160; 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 E537 Test Method for The Thermal Stability of Chemicals
by Differential Scanning Calorimetry
1.1 This test method determines the exothermic heat of
E967 Test Method for Temperature Calibration of Differen-
reaction of thermally reactive chemicals or chemical mixtures,
tial Scanning Calorimeters and Differential Thermal Ana-
using milligram specimen sizes, by differential scanning calo-
lyzers
rimetry. Such reactive materials may include thermally un-
E968 Practice for Heat Flow Calibration of Differential
stable or thermoset materials.
Scanning Calorimeters
1.2 This test method also determines the extrapolated onset
E1142 Terminology Relating to Thermophysical Properties
temperature and peak heat flow temperature for the exothermic
E1231 Practice for Calculation of Hazard Potential Figures-
reaction.
of-Merit for Thermally Unstable Materials
1.3 This test method may be performed on solids, liquids or E1860 Test Method for Elapsed Time Calibration of Ther-
mal Analyzers
slurries.
2.2 Other Standard:
1.4 Theapplicabletemperaturerangeofthismethodis25to
NAS 1613 Seal Element, Packing, Preformed, Ethylene
600°C.
Propylene Rubber, National Aerospace Standard, Aero-
1.5 The values stated in SI units are to be regarded as
space Industries Association of America, 1725 DeSales
standard. No other units of measurement are included in this
St., NM, Washington, DC 20036
standard.
3. Terminology
1.6 There is no ISO method equivalent to this standard.
3.1 Specifictechnicaltermsusedinthisstandardaredefined
1.7 This standard is related to Test Method E537 and to
in Terminologies E473 and E1142.
NAS 1613, but provides additional information.
1.8 This standard may involve hazardous materials,
4. Summary of Test Method
operations, and equipment. This standard does not purport to
4.1 A small (milligram) quantity of the reactive material is
address all of the safety concerns, if any, associated with its
heated at 10°C/min through a temperature region where a
use. It is the responsibility of the user of this standard to
chemical reaction takes place. The exothermic heat flow
establish appropriate safety and health practices and deter-
produced by the reaction is recorded as a function of tempera-
mine the applicability of regulatory limitations prior to use.
ture and time by a differential scanning calorimeter. Integration
of the exothermic heat flow over time yields the heat of
2. Referenced Documents
reaction. If the heat flow is endothermic, then this test method
2.1 ASTM Standards:
is not to be used.
E473 Terminology Relating to Thermal Analysis and Rhe-
4.2 The test method can be used to determine the fraction of
ology
a reaction that has occurred in a partially reacted sample. The
heat of reaction is determined for a specimen that is known to
be 100 % unreacted and is compared to the heat of reaction
ThistestmethodisunderthejurisdictionofASTMCommitteeE37onThermal
determined for the partially reacted sample. Appropriate cal-
Measurements and is the direct responsibility of Subcommittee E37.01 on Calo-
rimetry and Mass Loss.
culation yields the fraction of the latter sample that was
Current edition approved Sept. 1, 2012. Published September 2012. Originally
unreacted.
approved in 2001. Last previous edition approved in 2004 as E2160 – 04. DOI:
10.1520/E2160-04R12.
4.3 Subtracting the reaction fraction remaining from unity
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
(1) yields the fraction reacted. The fraction reacted may be
contact ASTM Customer service at service@astm.org. For Annual Book of ASTM
expressed as percent. If the sample tested is a thermoset resin,
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. the percent reacted is often called the percent of cure.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2160 − 04 (2012)
4.4 The extrapolated onset temperature and peak heat flow 7. Safety Precautions
temperature are determined for the exothermic heat flow
7.1 The use of this test method for materials of unknown
thermal curve from 4.1.
potential hazards requires that precautions be taken during the
sample preparation and testing.
5. Significance and Use
7.2 Where particle size reduction by grinding is necessary,
5.1 This method is useful in determining the extrapolated
the user of this test method shall presume that the material is
onset temperature, the peak heat flow temperature and the heat
hazardous.
of reaction of a material.Any onset temperature determined by
7.3 Toxic or corrosive effluents, or both, may be released
this method is not valid for use as the sole information used for
when heating the test specimen and could be harmful to
determination of storage or processing conditions.
personnelortheapparatus.Useofanexhaustsystemtoremove
5.2 This test method is useful in determining the fraction of
such effluents is recommended.
a reaction that has been completed in a sample prior to testing.
This fraction of reaction that has been completed can be a 8. Calibration
measure of the degree of cure of a thermally reactive polymer
8.1 Perform any calibration procedures recommended by
or can be a measure of decomposition of a thermally reactive
the apparatus manufacturer as described in the Operations
material upon aging.
Manual.
5.3 The heat of reaction values may be used in Practice
8.2 Calibrate the temperature signal to within 62°C using
E1231 to determine hazard potential figures-of-merit Explo-
Practice E967.
sion Potential and Shock Sensitivity.
8.3 Calibrate the heat flow signal to within 60.5 % using
5.4 This test method may be used in research, process
Practice E968.
control, quality assurance, and specification acceptance.
8.4 Calibrate the elapsed time signal, or ascertain its
accuracy, to within 60.5 % using Test Method E1860.
6. Apparatus
6.1 Differential Scanning Calorimeter (DSC), capable of 9. Procedure
measuringandrecordingheatflowasafunctionoftemperature
9.1 Into a tared sample container, weigh to within 61µg, 1
and time. Such a DSC is composed of:
to 2 mg of the test specimen. Record this mass as M in mg.
6.1.1 Test Chamber, composed of:
Close the sample. Weigh the sealed container to within 61µg
6.1.1.1 Furnace(s),toprovideuniformcontrolledheatingof
and recorded this mass as N in mg.
a specimen and reference to a constant temperature or at a
NOTE 2—Because of the reactive nature of the materials examined by
constant rate within the temperature range of 25 to 600°C.
this method, small specimen sizes shall be used unless the approximate
6.1.1.2 Temperature Sensor, to provide an indication of the
reactivity of the test specimen is known. Other specimen sizes may be
specimen or furnace temperature to within 60.5°C.
used but shall be reported. Make sure that the specimen is homogenous
6.1.1.3 Differential Sensor, to detect a heat flow difference
and represents the sample.
NOTE 3—Some substances may have non-reactive components mixed
between the specimen and reference equivalent to 0.2 mW.
with the thermally reactive material. An example would be reinforcing
6.1.1.4 Means of Sustaining a Test Chamber Environment,
fibers mixed with a thermally-curing polymer. A specification of the
of inert (for example, nitrogen, helium or argon) or reactive
fraction of inert material in the mixture may accompany these materials.
(for example, air) gas at a purge rate of 50 6 5 mL/min.
The user should be aware that such specifications involve tolerances so
that the actual fraction of inert material may vary within these tolerances
NOTE 1—Typically, at least 99 % pure nitrogen, helium or argon is
from lot to lot. In such cases, the actual fraction of inert material must be
employed when oxidation in air is a concern. Unless effects of moisture
taken into account.
are to be studied, use of dry purge gas is recommended.
NOTE 4—For highly reactive materials, the selection of sample con-
6.1.1.5 Temperature Controller, capable of executing a spe- tainers can be particularly important. The material from which the
containerisconstructedmaycatalyzethereactionorreactwiththesample
cific temperature program by operating the furnace(s) between
material. Sealed containers may cause an autocatalytic effect or possibly
selected temperature limits (ambient temperature to 600°C) at
a pressure effect. In open containers loss of material, and thereby loss of
a heating rate between 2 and 20°C/min constant to within
heat,couldbeanissue.Excessivepressurizationofasamplecontainercan
60.1°C/min.
be avoided by using vented containers, however, vented or unsealed
containers may cause the measured heat of reaction to be much smaller
6.1.1.6 RecordingDevice, capable of recording and display-
than the true value. see 12.4 for an example of such an effect.
ing any portion (including signal noise) of the differential heat
flow on the ordinate as a function of temperature or time on the 9.2 Heat the test specimen at a controlled rate of 10 6
abscissa. 0.1°C/min from ambient until the thermal curve returns to
baseline following the exothermic event. If the upper limit of
6.2 Containers, (pans, crucibles, vials, etc. and lids) that are
temperature for this method, 600°C, is reached before the
inert to the specimen and reference materials and that are of
thermal curve returns to baseline, then this method is not
suitable structural shape and integrity to contain the specimen
applicable.
and reference in accordance with the specific requirements of
this method.
NOTE 5—Other heating rates may be used but shall be reported.
6.3 Balance, with a capacity of 100 mg or greater to weigh 9.3 Cool the test specimen to ambient temperature upon
specimens and containers, or both, to a sensitivity of 61 µg. completion of the experiment.
E2160 − 04 (2012)
simultaneously, sample mass need be reduced only if the observe peak
9.4 Reweighthesamplecontainer.Comparethismassofthe
leans.
sealed sample container weight with N determined in 9.1.
Report any specimen weight loss observed. 9.7 Construct a tangent to the leading edge of the exother-
mic peak at the point of maximum rate of change and
...

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