DMA Master Curve Construction and the TTS Principle
Predicting Material Behavior Outside the Testable Frequency Range
Program:
- Introduction to material behavior
- Time-temperature equivalence and time-temperature superposition (TTS)
- The dependance of mechanical properties on the load frequency
- Master curve construction and the shift diagram
- Example applications
- Interactive Q&A
Understanding the viscoelastic behavior of materials under different loading conditions is crucial for effective material selection, processing, research, and quality control. However, instrument limitations mean it is not always possible to evaluate materials at extreme loading frequencies.
By employing the time-temperature superposition (TTS) technique to construct a DMA master curve, we can predict relaxation behavior beyond the capabilities of a dynamic mechanical analyzer. This approach provides valuable insights for material characterization and application development.
The Time-Temperature Superposition (TTS)
Changes in temperature can produce effects on the material's viscoelastic behavior that are comparable to those produced by changes in frequency or time. This principle, known as the time-temperature equivalence, allows for the interchange of frequency and temperature in the analysis of materials:
- Behavior at high frequencies (short time) is equivalent to behavior at low temperatures
- Behavior at low frequencies (long time) is equivalent to behavior at high temperatures
This forms the basis of the TTS technique, where data obtained at a certain temperature can be shifted along the frequency axis to predict behavior outside the measured range.
DMA master curve construction
By applying TTS, individual isothermal DMA curves measured across different frequency ranges are shifted horizontally towards a selected reference temperature curve to create a so-called master curve. The master curve represents a material's behavior beyond the frequency range that can be measured using standard DMA techniques. It can therefore be used to make predictions outside the conditions that were initially evaluated.
In this webinar, we explore the Williams–Landel–Ferry (WLF) model for master curve construction, as well as basic time and temperature equivalence, frequency dependence, and master-curve shift-diagram building using example applications.
We conclude with a Q&A session so don’t forget to prepare your questions!
- 24. 4. 2025 8:00, English
- 24. 4. 2025 16:00, English
Presenter: Dr. Andreas Bach
Andreas was awarded a PhD in Chemistry from the University of Bern in Switzerland and completed a postdoc at the University of Wisconsin-Madison Department of Chemistry, USA. In 2002, he accepted a position as a senior scientist and lecturer in physical organic chemistry in the Department of Chemistry and Applied Biosciences at ETH Zurich. In 2018, he joined METTLER TOLEDO as an application specialist for Thermal Analysis. In his current position, he expertly uses, teaches and supports DSC, TGA, TMA, and DMA instruments at the METTLER TOLEDO head office in Switzerland.
