Time-temperature superposition test parameters are used to determine the accuracy of fit
by Jonathan E. Martens and Kaylan Yaceczko, Akron Rubber Development Laboratory.
Research presented herein is a continuation of the research presented in a the article, “Optimization of test parameters for time temperature superposition testing and effect of heat history on superposition results,” published in the January 2024 issue of Rubber World (Vol. 269, No. 4). As discussed in the previous article, the time-temperature superposition (TTS) principle relates long test times for various viscoelastic properties at a desired operating temperature to short test times for the same properties at a higher temperature, and it relates very short test times at the desired operating temperature to longer test times at colder temperatures. For viscoelastic properties, the test time is best reflected in the frequency setting for the test. For example, if the available test instrument is capable of only 500 Hz, and characterization at 10 kHz is needed, those properties can be obtained utilizing this principle and testing at colder temperatures.