Fraunhofer Institute for Ceramic Technologies and Systems IKTS
Fraunhofer Institute for Ceramic Technologies and Systems IKTS

Temperature and time-dependent elasticity data

Topic

Dynamic mechanical analysis (DMA) is essentially used to characterize the temperature and time-dependent stiffness and elasticity of polymer materials. These "viscoelastic" properties vary greatly depending on their chemical basis and various additives. DMA is used to reliably determine the storage modulus (modulus of elasticity of polymers) and the glass transition range.

Dynamic mechanical analyzer "DMA Q800" from TA Instruments.
© Fraunhofer IKTS
Dynamic mechanical analyzer "DMA Q800" from TA Instruments.
Stiffness measurement of barrier films in tensile mode under the influence of moisture.
© Fraunhofer IKTS
Stiffness measurement of barrier films in tensile mode under the influence of moisture.
3-point bending measurement of thick film pastes on an aluminum oxide substrate to determine the stiffness of thin films.
© Fraunhofer IKTS
3-point bending measurement of thick film pastes on an aluminum oxide substrate to determine the stiffness of thin films.
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Selection support for polymer materials

  • Identification of materials for the specific operating temperature range and with high resistance to ageing effects
  • Characterization of aging effects due to temperature changes, humidity/heat, salt spray or media aging
  • Measurement of the storage modulus and the glass transition area (Tg) as a function of temperature and frequency
  • Load-dependent (tension/bending)
For ideal materials, the glass transition is outside the operating temperature range.
© Fraunhofer IKTS
For ideal materials, the glass transition is outside the operating temperature range.
Example of post-crosslinking of the polymer, detectable by DMA measurement.
© Fraunhofer IKTS
Example of post-crosslinking of the polymer, detectable by DMA measurement.
Frequency response of stiffness measurement shows time dependence.
© Fraunhofer IKTS
Frequency response of stiffness measurement shows time dependence.

Characterization procedure for modeling linear viscoelastic behavior

  • Multiple measurement of at least three samples to minimize post-crosslinking processes
  • Selection of the best sample for characterization
  • Carrying out a time- and temperature-dependent storage modulus measurement (Prony measurement)
  • Extraction of the necessary parameters for viscoelastic material model (generally valid)
  • Data preparation for FEM structural simulation as ready-to-use micro (e.g., Ansys)
Prony measurement.
© Fraunhofer IKTS
Prony measurement.
Extraction of parameters.
© Fraunhofer IKTS
Extraction of parameters.
Plausibility check.
© Fraunhofer IKTS
Plausibility check.

System specification for dynamic mechanical analysis (DMA)

Dynamic mechanical analysis (DMA)
Device: Q800 from TA Instruments Displacement resolution:  1 nm Heating rate:  0,1 to 10 K/min
Maximum force:  18 N Frequency range:  0,01 bis 200 Hz Cooling rate:  0,1 to 10 K/min
Minimum force:  0,0001 N Deformation range: ±0,5 µm to 10 mm Temperature stability:  0,1 K
Force resolution:  0,00001 N Temperature range:  -150 to 600 °C    

 

DMA with humidity control module
Temperature range:  5 to 120 °C Cooling rate: 0,1 to 1 K/min Humidity accuracy: 5 to 90 % r. H. ± 5 % r. H.
Temperature accuracy: ± 0,5 K Humidity control: 5 bis 95 % r. H. Humidity control: 2 % r. H./min
Heating rate: 0,1 bis 1 K/min        

 

Loading options
Tensile (film and fiber) | Tension in liquid medium | 3- or 4-point bending | cantilever | compression