ASTM E1824-19

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Designation: E1824 − 18 E1824 − 19
Standard Test Method for
Assignment of a Glass Transition Temperature Using
Thermomechanical Analysis: Tension Method
This standard is issued under the fixed designation E1824; 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 This test method describes a procedure for the assignment of a glass transition temperature (T ) of materials on heating using
g
thermomechanical measurements in tension.
1.2 This test method may be used as a complement to Test Method E1545 and is applicable to amorphous or to partially
crystalline materials in the form of films, fibers, wires, etc., that are sufficiently rigid to inhibit extension during loading at ambient
temperature.
1.3 The generally applicable temperature range for this test method is −10025 °C to 600 °C. This temperature range may be
altered depending upon the instrumentation used.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.6 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
E1545 Test Method for Assignment of the Glass Transition Temperature by Thermomechanical Analysis
E2602 Test Methods for the Assignment of the Glass Transition Temperature by Modulated Temperature Differential Scanning
Calorimetry
3. Terminology
3.1 Definitions:
3.1.1 The following terms are applicable to this test method and can be found in Terminology E473 and Terminology E1142:
thermomechanical analysis (TMA), thermodilatometry, glass transition, and glass transition temperature.
4. Summary of Test Method
4.1 This test method uses thermomechanical analysis equipment (thermomechanical analyzer, dilatometer, or similar device)
with the test specimen in tension to determine the change in dimension of a thin specimen observed when the material is subjected
to a constant heating rate through the glass transition region. This change in dimension associated with the change from vitreous
solid to amorphous liquid is observed as movement of a sensing probe in direct contact with the specimen and is recorded as a
This test method is under the jurisdiction of ASTM Committee E37 on Thermal Measurements and is the direct responsibility of Subcommittee E37.10 on Fundamental,
Statistical and Mechanical Properties.
Current edition approved Aug. 1, 2018Sept. 1, 2019. Published August 2018September 2019. Originally approved in 1996. Last previous edition approved in 20132018
as E1824 – 13.E1824 – 18. DOI: 10.1520/E1824-18.10.1520/E1824-19.
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
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1824 − 19
function of temperature. The intersection of the extrapolation of the slope of the probe displacement curve before and after the
transition is used to determine a temperature that is assigned as the glass transition temperature.
5. Significance and Use
5.1 The glass transition is dependent on the thermal history, softening agents or additives of the material to be tested. For
amorphous and semicrystalline materials the assignment of a glass transition temperature may lead to important information about
thermal history, processing conditions, stability, progress of chemical reactions, and mechanical and electrical behavior.
5.2 Thermomechanical analysis provides a rapid means of detecting changes in hardness or linear dimensional change
associated with the glass transition. Dimensional changes measured as a specimen is heated over the glass transition region may
include the interaction of several effects: an increase in the coefficient of expansion, a decrease in the modulus, which under a
constant stress leads to increased extension, stress relief leading to irreversible dimensional change (shrinkage in one dimension,
expansion in another dimension), and physical aging effects which change the kinetics of the dimensional change.
5.3 This test method is useful for research and development, quality control, and specification acceptance testing; particularly
of films and fibers.
6. Interferences
6.1 This test method may be used for materials having a glass transition at or below ambient temperature providing care is taken
to avoid exposing the specimen to a tensile force prior to cooling the specimen below its glass transition. Applying a tensile load
on a specimen that is above its glass transition will result in elongation of the specimen which may introduce orientation and
residual stresses that will alter the specimen thermal history and may yield erroneous results during the heating cycle.
6.2 Specimens of thickness less than 0.2 mm may be difficult to handle.
6.3 Specimens of thickness greater than 5 mm may develop temperature nonuniformities of sufficient extent as to yield
erroneously high values for an assigned glass transition temperature using this test method.
7. Apparatus
7.1 The essential equipment required to provide the minimum instrument capability for this test method includes:
7.1.1 A Thermomechanical Analyzer (TMA) or Thermodilatometer, consisting of:
7.1.1.1 Rigid Specimen Holder, of inert, low expansivityexpansion material (≤20 μm ⁄m-°C), usually quartz, to center the
specimen in the furnace and to fix the specimen to mechanical ground.
NOTE 1—Use of rigid specimen holders and tension probes constructed of lower thermal expansivityexpansion (≤20 μm ⁄m-°C) materials or corrections
for hardware expansivityexpansion may be necessary if very small changes in specimen dimensions are encountered with this test method.
7.1.1.2 Rigid Tension Probe, of inert, low expansivityexpansion material (≤ 5 μm ⁄m-°C), usually quartz, which contacts the
specimen with an applied in-plane tensile force.
7.1.1.3 Sensing Element, with a dynamic range of at least 5 mm,4 mm, a linearity of 1 % or better, and sufficient sensitivity to
measure the displacement of the rigid tension probe within 61 μm resulting from changes in length of the specimen.
7.1.1.4 Weight or Force Transducer, to generate a constant force between 0 mN and 50 mN 6 2 % that is applied through the
rigid tension probe to the specimen.
7.1.1.5 Furnace and Temperature Controller, capable of executing a temperature program of uniform controlled heating of a
specimen at a constant rate of 5 °C/min 6 0.2 °C/min between required temperature limits to 60.5 °C.
7.1.1.6 Temperature Sensor, that can be positioned reproducibly in close proximity to the specimen to measure its temperature
between −10025 °C and 600 °C readable with a resolution of to within 60.1 °C.
7.1.1.7 Means of Providing a Specimen Environment, of an inert gas at a purge rate of 10 mL/min to 50 mL ⁄min 6 5 %. The
typical purge gas rate is usually given by the instrument manufacturer.
NOTE 2—Typically 99.99 % pure nitrogen, argon, or helium is employed when oxidation in air is a concern. Unless effects of moisture are to be studied,
use of dry purge gas is recommended; especially for operation at subambient temperatures. Calibration shall be performed Perform the calibration using
the same purge gas to be used with test specimens.
7.1.1.8 Data Collection Device, provide a means of acquiring, storing, and displaying measured or calculated signals, or both.
The minimum output signals required for thermomechanical analysis are dimension change, temperature and time.
7.1.2 Rigid Specimen Clamps, (clamps, grips, pins, or split shot) of inert, low expansivityexpansion material (≤ 20 μm ⁄m-°C)
that grip the specimen between the rigid specimen holder and the rigid tension probe without distortion (<1 %) or slippage (<1 %).
7.2 Auxiliary equipment considered useful in conducting this test method includes:
7.2.1 Coolant System, that can be coupled directly to the furnace/temperature controller to hasten recovery from elevated
temperatures, to provide controlled cooling rates constant to 61.0 °C/min, and to sustain a subambient temperature to 60.5 °C.
7.2.2 Calipers,
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