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TMA 402 F1/F3 Hyperion® - Thermomechanical Analyzer

 

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Meaningful Material Characterization
in the Low-Temperature Fields

Tension Test on a Polymer Film
Orientation effects, stretch conditions and shrinkage are measured under load for films. In this example, the expansion and contraction behavior of a 40-μm thick polycarbonate film was tested under tensile load. The results varied considerably depending on the load. Under low amounts of force (5 mN), the film contracted at higher temperatures; however, it expanded if greater force (50 mN) was applied.

Behavior of Polymers under Pressure
The extent to which the elastic properties of a seal remain intact after being subjected to a constant load of longer duration is very important. To test this, an elastomer seal was loaded with a force of 3 N and then relieved to 5 mN. Following a 40-hour load time, 21% compression was observed. After a 30-minute relief period, the compression had reversed by 16.2%; after 60 min, by 16.8%. The visco-elastic properties of the elastomer were such that the sample did not return to its original length even after 30 hours.

Visco-Elastic Properties of Polytetrafluoroethylene
The combination of a 3-point bending sample holder and a modulated sample force allows the visco-elastic properties of a material to be determined. A PTFE bar was measured between -150°C and 150°C under (rectangular) modulated force (fixed static force of 0.2 N and three different dynamic forces). Based on the expansion data and the sample geometry, the storage
modulus E´ can be calculated as a function of temperature. The three typical PTFE transformations are clearly visible at around -100°C (ß-transition), between 0°C and 50°C (crystal to condis-crystal transformation) and above 100°C (glass transition).

Meaningful Material Characterization in the High-Temperature Field

Sintering of Aluminum Titanate
One use of aluminum titanate is as a carrier material for catalytic converters in the automobile industry. Shown here is the measurement of an aluminum titanate green body in the temperature range from RT to 1450°C with a subsequent isothermal line at 1450°C of 7 hours. During the heating, shrinkage of 12.7% is observed. The sintering takes place in 2 steps with a maximum sintering rate of 0.31%/min. In the subsequent isothermal phase, further shrinkage of 0.6% occurs. To optimize the sintering process, an RCS measurement (rate controlled sintering; optionally available) can additionally be carried out.

Measurement with EGA (Evolved Gas Analysis)
A clay sample (powder) was tested in air using a TMA-MS (Aëolos®) coupling in the temperature range from RT to 800°C. At the beginning of the measurement, the adsorptively bound water and the interlayer water are released (shrinkage of 0.01%). Above 300°C, the sample’s organic constituents burn up (maxima in the curves for m18, water, and m44, CO₂). There is no visible influence on the expansion curve here, due to the very low proportion. Between 487°C and 536°C, dehydroxylation of the sample’s clay mineral content takes place. Associated with that is a sample shrinkage of 0.05%.

Please also visit the following product pages:

DIL 402 PC

DIL 402 C

DMA 242 C