ASTM D7028-07(2015)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D7028 − 07 (Reapproved 2015)
Standard Test Method for
Glass Transition Temperature (DMA Tg) of Polymer Matrix
Composites by Dynamic Mechanical Analysis (DMA)
This standard is issued under the fixed designation D7028; 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 D4065 Practice for Plastics: Dynamic Mechanical Proper-
ties: Determination and Report of Procedures
1.1 This test method covers the procedure for the determi-
D4092 Terminology for Plastics: Dynamic Mechanical
nation of the dry or wet (moisture conditioned) glass transition
Properties
temperature (T ) of polymer matrix composites containing
g
6 D5229/D5229M Test Method for Moisture Absorption Prop-
high-modulus, 20 GPa (> 3 × 10 psi), fibers using a dynamic
erties and Equilibrium Conditioning of Polymer Matrix
mechanical analyzer (DMA) under flexural oscillation mode,
Composite Materials
which is a specific subset of the Dynamic Mechanical Analysis
E177 Practice for Use of the Terms Precision and Bias in
(DMA) method.
ASTM Test Methods
1.2 The glass transition temperature is dependent upon the
E691 Practice for Conducting an Interlaboratory Study to
physical property measured, the type of measuring apparatus
Determine the Precision of a Test Method
and the experimental parameters used. The glass transition
E1309 Guide for Identification of Fiber-Reinforced
temperature determined by this test method (referred to as
Polymer-Matrix Composite Materials in Databases (With-
“DMA Tg”) may not be the same as that reported by other
drawn 2015)
measurement techniques on the same test specimen.
E1434 Guide for Recording Mechanical Test Data of Fiber-
1.3 This test method is primarily intended for polymer Reinforced Composite Materials in Databases (Withdrawn
2015)
matrix composites reinforced by continuous, oriented, high-
modulus fibers. Other materials, such as neat resin, may require E1471 Guide for Identification of Fibers, Fillers, and Core
Materials in Computerized Material Property Databases
non-standard deviations from this test method to achieve
meaningful results. (Withdrawn 2015)
E1640 Test Method for Assignment of the Glass Transition
1.4 The values stated in SI units are standard. The values
Temperature By Dynamic Mechanical Analysis
given in parentheses are non-standard mathematical conver-
E1867 Test Method for Temperature Calibration of Dynamic
sions to common units that are provided for information only.
Mechanical Analyzers
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Definitions—Terminology D3878 defines terms relating
priate safety and health practices and determine the applica-
to polymer matrix composites. Terminology D4092 defines
bility of regulatory limitations prior to use.
terms relating to dynamic mechanical property measurements
on polymeric materials.
2. Referenced Documents
3.2 Symbols: E’ = storage modulus
2.1 ASTM Standards:
E” = loss modulus
D3878 Terminology for Composite Materials
tan δ = E”/E’ = tangent delta
DMA Tg = glass transition temperature defined from dy-
namic mechanical analysis measurement
This test method is under the jurisdiction of ASTM Committee D30 on
L = length of specimen
Composite Materials and is the direct responsibility of Subcommittee D30.04 on
Lamina and Laminate Test Methods. W = width of specimen
Current edition approved Aug. 1, 2015. Originally approved in 2007. Last
T = thickness of specimen
ε1
previous edition approved in 2007 as D7028-07 . Published August 2015. DOI:
T = peak temperature from tangent delta curve
t
10.1520/D7028-07E01R15.
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’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7028 − 07 (2015)
4. Summary of Test Method noted and reported. The same conditions shall be used for both
calibration and testing runs. Instrumentation manufacturer
4.1 A flat rectangular strip of laminate is placed in the DMA
recommendations should be followed.
equipment and oscillated at a nominal frequency of 1 Hz. The
specimen is heated at a rate of 5°C/min (9°F/min). The same
6.5 It is standard in this test method that one of the major
loading frequency and heating rate is used for both dry and wet
fiber directions shall be parallel to the length of the specimen.
specimens (moisture conditioned) to allow for comparison.
The span-to-depth ratio, ply orientation, and ply stacking
The temperature at which a significant drop in storage modulus sequence of a specimen with respect to the testing fixture have
(E’) begins is assigned as the glass transition temperature
a profound effect on the DMA Tg result. A meaningful
(DMA Tg). The peak temperature of the tangent delta curve comparison of data requires that the specimen configuration be
(T ) is identified along with DMA Tg for comparison purposes.
the same. A non-standard specimen configuration shall be
t
described in the report and the result recorded as non-standard.
5. Significance and Use
6.6 The standard definition in this test method for DMA Tg
5.1 This test method is designed to determine the glass
is based on intersecting two tangent lines from a semi-
transition temperature of continuous fiber reinforced polymer
logarithmic plot of the storage modulus versus temperature.
composites using the DMA method. The DMA Tg value is
Other T definitions typically produce different test results. For
g
frequently used to indicate the upper use temperature of
example, a linear plot scale will result in a lower value of DMA
composite materials, as well as for quality control of composite
Tg. A non-standard DMA Tg definition shall be described in
materials.
the report and the result recorded as non-standard. For com-
parison purposes the peak temperature of the tangent delta
6. Interferences
curve (T ) is identified along with DMA Tg.
t
6.1 The standard testing machine shall be of the Dynamic
Mechanical Analysis (DMA) type of instrument that operates 7. Apparatus
with forced oscillation and applies a flexural loading mode
7.1 Micrometer, suitable for reading to 0.025 mm (0.001 in.)
(either three-point bend or dual cantilever) to the test specimen.
accuracy for measuring the specimen thickness and width.
Refer to Practice D4065 for a summary of various other DMA
7.2 Caliper, suitable for reading to 0.025 mm (0.001 in.)
practices. Other loading modes (such as tensile, torsion or
accuracy for measuring the specimen length and instrument
shear) may produce different test results. If another equipment
clamping distance.
type or loading mode is used the non-standard approach shall
be described in the report and the test result recorded as
7.3 Dynamic Mechanical Analyzer (DMA), with oven ca-
non-standard.
pable of heating to above the glass transition temperature and
of controlling the heating rate to the specified value.
6.2 A fixed frequency of 1 Hz is standard in this test method.
In general, for a given material, a higher testing frequency
8. Sampling and Test Specimens
produces a higher DMA Tg value than this standard, while use
of the resonance mode will yield a different DMA Tg that may
8.1 Two specimens shall be tested for each sample. If the
be either higher or lower than the standard. If a non-standard
testing is part of a designed experiment, other sampling
frequency, or the resonance mode, is used, the non-standard
techniques may be used if described in the test plan.
approach shall be described in the report and the test result
8.2 Consult the instrument manufacturer’s manual for speci-
recorded as non-standard.
men size. A span-to-thickness ratio greater than ten is recom-
6.3 A heating rate of 5 6 1°C/min (9 6 2°F/min) is standard
mended. Specimen absolute size is not fixed by this method as
in this test method. A change in heating rate will affect the glass
various dynamic mechanical analyzers require different sizes.
transition temperature result; the standard heating rate is the
Depending on the analyzer, typical specimen size can range
best available compromise for comparing DMA Tg results of
from 56 6 4 × 12 6 1 × 2.0 6 0.5 mm (2.21 6 0.16 × 0.47
dry and wet laminates. If a different heating rate is used it shall
6 0.04 × 0.08 6 0.02 in.) (L × W × T) to 22 6 1 × 3 6 1 ×
be described in the report and the result recorded as non-
1.0 6 0.5 mm (0.9 6 0.04 × 0.12 6 0.04 × 0.04 6 0.02 in.).
standard.
8.3 One of the major fiber directions in the specimen shall
NOTE 1—Users should be advised that a heating rate of 5°C/min
represents a compromise between various issues related to Tg measure-
be oriented along the length axis of the specimen. It is standard
ment precision and bias. It is widely known that heat transfer limitations
that one of the major fiber directions shall be parallel to the
are more pronounced in DMA apparatus compared to other thermal
length of the specimen, and specimens containing only off-axis
analysis techniques, such as differential scanning calorimetry (DSC) and
plies shall not be used. Any deviations from the standard
thermomechanical analysis (TMA). For greatest precision, it has been
recommended that heating rates be 2°C/min or less. Test Method E1640 orientation shall be reported and the test results noted as
specifies a heating rate of 1°C/min. However, in many cases 5°C/min is
non-standard.
recommended as a compromise between Tg measurement accuracy and
8.4 The specimen surfaces shall be flat, clean, straight, and
test method convenience, especially for wet laminate measurements, since
the slower heating rate will cause specimen drying that will itself bias the
dry to prevent slippage in the grips and mitigate any effects due
results.
to moisture. Opposite surfaces must be essentially parallel and
6.4 Purge gas type and flow rate and the position of the intersecting surfaces perpendicular. Tolerances in thickness and
thermocouple can affect the DMA Tg test result and shall be width must be better than 62 %.
D7028 − 07 (2015)
8.5 The selected sample shall be taken from a representative 11.4 Heating Rate—The standard heating rate is 5 6 1°C/
portion of the laminate. Laminate edges or other irregularities min (9 6 2°F/min). The same heating rate shall be used for all
created in the laminate by mold or bagging techniques should samples whose results are to be compared. Any deviations
be avoided. from this heating rate shall be noted in the report and the result
shall be reported as non-standard.
9. Calibration
11.5 Frequency—The standard frequency to be used in this
9.1 The DMA equipment shall be calibrated in accordance
standard is 1 Hz, and the instrument should be operated in
with Test Method E1867 for temperature signals and in
constant strain mode.
accordance with the equipment manufacturer’s recommenda-
11.6 Strain Amplitude—The maximum strain amplitude
tion for the storage modulus. The equipment must be calibrated
should be kept within the linear viscoelastic range of the
in the same loading mode as will be used for testing, either dual
material. Strains of less than 0.1 % are standard.
cantilever or three-point bending. The temperature calibration
11.7 Temperature Range—Program the run to begin at room
points must span the DMA Tg result.
temperature or a temperature at least 50°C (90°F) below the
estimated DMA Tg and to end at a temperature at least 50°C
10. Conditioning
(90°F) above DMA Tg, but below decomposition temperature.
10.1 Moisture has significant effect on DMA Tg. Therefore,
11.8 Purge Gas Flow Rate—Follow the manufacturer’s
it is recommended that the test specimens should be weighed
manual or recommendations to set the purge gas flow rate. Five
before and after DMA Tg testing to quantify the moisture
litres/minute (0.2 CFM) is a typical purge gas flow rate setting.
change in the specimen resulting from the DMA Tg test.
For some types of dynamic mechanical analyzers, a purge gas
10.2 Dry Specimens—To minimize the presence of moisture
flow setting is not required.
in the specimens, dry specimens must be conditioned prior to
11.9 Thermocouple Positioning—Follow the manufacturer’s
testing by using either of the following techniques:
manual or recommendations to position the thermocouple.
10.2.1 Dry the specimens in an oven in accordance with
Typically the thermocouple should be as close to the sample as
Test Method D5229/D5229M, Procedure D, then stored until
possible.
test in a desiccator or sealed MIL-PRF-131 (or equivalent)
aluminized bag, or
11.10 Test—Conduct DMA Tg measurements using the
10.2.2 Store the material in a desiccator or sealed alumi- instrument settings specified and record the load and displace-
nized bag immediately after material curing (lamination),
ment data as a function of temperature. Allow the oven to cool
where the material shall remain except for the minimum time
before removing the specimen. Weigh the specimen after the
required for removal during specimen preparation and testing.
test to the nearest milligram (0.001 g) after the removal from
The maximum time between cure (lamination) and testing shall
the oven and record.
be 30 days, after which, prior to testing, specimens shall be
11.11 Specimen Examination—Examine the specimen after
oven-dried in accordance with 10.2.1.
the test and inspect for any visual anomalies (that is,
10.3 Wet Specimens—Condition in accordance with Test delamination, blisters, cracks, etc.). Record any visual anoma-
Method D5229/D5229M, Procedure B. The conditioned speci- lies observed.
mens shall be tested within 30 minutes after removal from the
12. Interpretation of Results
conditioning chamber, or stored in sealed MIL-PRF-131 (or
12.1 Glass Transition Temperature (DMA Tg)—Plot the
equivalent) aluminized bag until test.
logarithm of storage modulus (E’) and linear tangent delta (tan
11. Procedure δ) versus the linear temperature (Fig. 1). During the glass
transition, the storage modulus of the composite material is
11.1 Test Specimen—Measure the specimen thickness and
significantly reduced. The DMA Tg is determined to be the
width to 0.025 mm (0.001 in.)
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: D7028 − 07 D7028 − 07 (Reapproved 2015)
Standard Test Method for
Glass Transition Temperature (DMA Tg) of Polymer Matrix
Composites by Dynamic Mechanical Analysis (DMA)
This standard is issued under the fixed designation D7028; 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.
ε NOTE—Reference to a research report was added and figures corrected in August 2008.
1. Scope
1.1 This test method covers the procedure for the determination of the dry or wet (moisture conditioned) glass transition
temperature (T ) of polymer matrix composites containing high-modulus, 20 GPa (> 3 × 10 psi), fibers using a dynamic
g
mechanical analyzer (DMA) under flexural oscillation mode, which is a specific subset of the Dynamic Mechanical Analysis
(DMA) method.
1.2 The glass transition temperature is dependent upon the physical property measured, the type of measuring apparatus and the
experimental parameters used. The glass transition temperature determined by this test method (referred to as “DMA Tg”) may not
be the same as that reported by other measurement techniques on the same test specimen.
1.3 This test method is primarily intended for polymer matrix composites reinforced by continuous, oriented, high-modulus
fibers. Other materials, such as neat resin, may require non-standard deviations from this test method to achieve meaningful results.
1.4 The values stated in SI units are standard. The values given in parentheses are non-standard mathematical conversions to
common units that are provided for information only.
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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D3878 Terminology for Composite Materials
D4065 Practice for Plastics: Dynamic Mechanical Properties: Determination and Report of Procedures
D4092 Terminology for Plastics: Dynamic Mechanical Properties
D5229/D5229M Test Method for Moisture Absorption Properties and Equilibrium Conditioning of Polymer Matrix Composite
Materials
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E1309 Guide for Identification of Fiber-Reinforced Polymer-Matrix Composite Materials in Databases (Withdrawn 2015)
E1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in Databases (Withdrawn 2015)
E1471 Guide for Identification of Fibers, Fillers, and Core Materials in Computerized Material Property Databases (Withdrawn
2015)
E1640 Test Method for Assignment of the Glass Transition Temperature By Dynamic Mechanical Analysis
E1867 Test Method for Temperature Calibration of Dynamic Mechanical Analyzers
This test method is under the jurisdiction of ASTM Committee D30 on Composite Materials and is the direct responsibility of Subcommittee D30.04 on Lamina and
Laminate Test Methods.
ε1
Current edition approved Dec. 15, 2007Aug. 1, 2015. Originally approved in 2007. Last previous edition approved in 2007 as D7028-07 . Published January 2008August
2015. DOI: 10.1520/D7028-07E01.10.1520/D7028-07E01R15.
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’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7028 − 07 (2015)
3. Terminology
3.1 Definitions—Terminology D3878 defines terms relating to polymer matrix composites. Terminology D4092 defines terms
relating to dynamic mechanical property measurements on polymeric materials.
3.2 Symbols: E’ = storage modulus
E” = loss modulus
tan δ = E”/E’ = tangent delta
DMA Tg = glass transition temperature defined from dynamic mechanical analysis measurement
L = length of specimen
W = width of specimen
T = thickness of specimen
T = peak temperature from tangent delta curve
t
4. Summary of Test Method
4.1 A flat rectangular strip of laminate is placed in the DMA equipment and oscillated at a nominal frequency of 1 Hz. The
specimen is heated at a rate of 5°C/min (9°F/min). The same loading frequency and heating rate is used for both dry and wet
specimens (moisture conditioned) to allow for comparison. The temperature at which a significant drop in storage modulus (E’)
begins is assigned as the glass transition temperature (DMA Tg). The peak temperature of the tangent delta curve (T ) is identified
t
along with DMA Tg for comparison purposes.
5. Significance and Use
5.1 This test method is designed to determine the glass transition temperature of continuous fiber reinforced polymer composites
using the DMA method. The DMA Tg value is frequently used to indicate the upper use temperature of composite materials, as
well as for quality control of composite materials.
6. Interferences
6.1 The standard testing machine shall be of the Dynamic Mechanical Analysis (DMA) type of instrument that operates with
forced oscillation and applies a flexural loading mode (either three-point bend or dual cantilever) to the test specimen. Refer to
Practice D4065 for a summary of various other DMA practices. Other loading modes (such as tensile, torsion or shear) may
produce different test results. If another equipment type or loading mode is used the non-standard approach shall be described in
the report and the test result recorded as non-standard.
6.2 A fixed frequency of 1 Hz is standard in this test method. In general, for a given material, a higher testing frequency
produces a higher DMA Tg value than this standard, while use of the resonance mode will yield a different DMA Tg that may be
either higher or lower than the standard. If a non-standard frequency, or the resonance mode, is used, the non-standard approach
shall be described in the report and the test result recorded as non-standard.
6.3 A heating rate of 5 6 1°C/min (9 6 2°F/min) is standard in this test method. A change in heating rate will affect the glass
transition temperature result; the standard heating rate is the best available compromise for comparing DMA Tg results of dry and
wet laminates. If a different heating rate is used it shall be described in the report and the result recorded as non-standard.
NOTE 1—Users should be advised that a heating rate of 5°C/min represents a compromise between various issues related to Tg measurement precision
and bias. It is widely known that heat transfer limitations are more pronounced in DMA apparatus compared to other thermal analysis techniques, such
as differential scanning calorimetry (DSC) and thermomechanical analysis (TMA). For greatest precision, it has been recommended that heating rates be
2°C/min or less. Test Method E1640 specifies a heating rate of 1°C/min. However, in many cases 5°C/min is recommended as a compromise between
Tg measurement accuracy and test method convenience, especially for wet laminate measurements, since the slower heating rate will cause specimen
drying that will itself bias the results.
6.4 Purge gas type and flow rate and the position of the thermocouple can affect the DMA Tg test result and shall be noted and
reported. The same conditions shall be used for both calibration and testing runs. Instrumentation manufacturer recommendations
should be followed.
6.5 It is standard in this test method that one of the major fiber directions shall be parallel to the length of the specimen. The
span-to-depth ratio, ply orientation, and ply stacking sequence of a specimen with respect to the testing fixture have a profound
effect on the DMA Tg result. A meaningful comparison of data requires that the specimen configuration be the same. A
non-standard specimen configuration shall be described in the report and the result recorded as non-standard.
6.6 The standard definition in this test method for DMA Tg is based on intersecting two tangent lines from a semi-logarithmic
plot of the storage modulus versus temperature. Other T definitions typically produce different test results. For example, a linear
g
plot scale will result in a lower value of DMA Tg. A non-standard DMA Tg definition shall be described in the report and the result
recorded as non-standard. For comparison purposes the peak temperature of the tangent delta curve (T ) is identified along with
t
DMA Tg.
D7028 − 07 (2015)
7. Apparatus
7.1 Micrometer, suitable for reading to 0.025 mm (0.001 in.) accuracy for measuring the specimen thickness and width.
7.2 Caliper, suitable for reading to 0.025 mm (0.001 in.) accuracy for measuring the specimen length and instrument clamping
distance.
7.3 Dynamic Mechanical Analyzer (DMA), with oven capable of heating to above the glass transition temperature and of
controlling the heating rate to the specified value.
8. Sampling and Test Specimens
8.1 Two specimens shall be tested for each sample. If the testing is part of a designed experiment, other sampling techniques
may be used if described in the test plan.
8.2 Consult the instrument manufacturer’s manual for specimen size. A span-to-thickness ratio greater than ten is recommended.
Specimen absolute size is not fixed by this method as various dynamic mechanical analyzers require different sizes. Depending
on the analyzer, typical specimen size can range from 56 6 4 × 12 6 1 × 2.0 6 0.5 mm (2.21 6 0.16 × 0.47 6 0.04 × 0.08 6
0.02 in.) (L × W × T) to 22 6 1 × 3 6 1 × 1.0 6 0.5 mm (0.9 6 0.04 × 0.12 6 0.04 × 0.04 6 0.02 in.).
8.3 One of the major fiber directions in the specimen shall be oriented along the length axis of the specimen. It is standard that
one of the major fiber directions shall be parallel to the length of the specimen, and specimens containing only off-axis plies shall
not be used. Any deviations from the standard orientation shall be reported and the test results noted as non-standard.
8.4 The specimen surfaces shall be flat, clean, straight, and dry to prevent slippage in the grips and mitigate any effects due to
moisture. Opposite surfaces must be essentially parallel and intersecting surfaces perpendicular. Tolerances in thickness and width
must be better than 62 %.
8.5 The selected sample shall be taken from a representative portion of the laminate. Laminate edges or other irregularities
created in the laminate by mold or bagging techniques should be avoided.
9. Calibration
9.1 The DMA equipment shall be calibrated in accordance with Test Method E1867 for temperature signals and in accordance
with the equipment manufacturer’s recommendation for the storage modulus. The equipment must be calibrated in the same
loading mode as will be used for testing, either dual cantilever or three-point bending. The temperature calibration points must span
the DMA Tg result.
10. Conditioning
10.1 Moisture has significant effect on DMA Tg. Therefore, it is recommended that the test specimens should be weighed before
and after DMA Tg testing to quantify the moisture change in the specimen resulting from the DMA Tg test.
10.2 Dry Specimens—To minimize the presence of moisture in the specimens, dry specimens must be conditioned prior to
testing by using either of the following techniques:
10.2.1 Dry the specimens in an oven in accordance with Test Method D5229/D5229M, Procedure D, then stored until test in
a desiccator or sealed MIL-PRF-131 (or equivalent) aluminized bag, or
10.2.2 Store the material in a desiccator or sealed aluminized bag immediately after material curing (lamination), where the
material shall remain except for the minimum time required for removal during specimen preparation and testing. The maximum
time between cure (lamination) and testing shall be 30 days, after which, prior to testing, specimens shall be oven-dried in
accordance with 10.2.1.
10.3 Wet Specimens—Condition in accordance with Test Method D5229/D5229M, Procedure B. The conditioned specimens
shall be tested within 30 minutes after removal from the conditioning chamber, or stored in sealed MIL-PRF-131 (or equivalent)
aluminized bag until test.
11. Procedure
11.1 Test Specimen—Measure the specimen thickness and width to 0.025 mm (0.001 in.) and record. Measure the specimen
length to 0.025 mm (0.001 in.) and record. Weigh the specimen to the nearest milligram (0.001 g) and record.
11.2 Specimen Installation—Install the specimen in the DMA test equipment oven based upon clamping method to be
employed.
11.3 Positioning of Specimen—Follow the manufacturer’s procedure for positioning the specimen in the clamps. Generally, the
specimen should be centered between the clamp faces and be parallel to the base of the instrument. Mount the specimen in dual
cantilever mode or three-point bending mode.
MIL-PRF-131, Barrier Materials, Watervaporproof, Greaseproof, Flexible, Heat-Sealable. Available at http://assist.daps.dla.mil or from the Standardization Document
Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.
D7028 − 07 (2015)
11.4 Heating Rate—The standard heating rate is 5 6 1°C/min (9 6 2°F/min). The same heating rate shall be used for all samples
whose results are to be compared. Any deviations from this heating rate shall be noted in the report and the result shall be reported
as non-standard.
11.5 Frequency—The standard frequency to be used in this standard is 1 Hz, and the instrument should be operated in constant
strain mode.
11.6 Strain Amplitude—The maximum strain amplitude should be kept within the linear viscoelastic range of the material.
Strains of less than 0.1 % are standard.
11.7 Temperature Range—Program the run to begin at room temperature or a temperature at least 50°C (90°F) below the
estimated DMA Tg and to end at a temperature at least 50°C (90°F) above DMA Tg, but below decomposition temperature.
11.8 Purge Gas Flow Rate—Follow the manufacturer’s manual
...