Time-temperature superposition method for glass transition temperature of plastic materials

A new method has been proposed to determine glass transition temperature of plastic materials complying time-temperature superposition (TTS) with a dynamic mechanical analyser (DMA). The principle of this new method is to detect the change in response of plastic materials to multi-frequency dynamic loading over glass transition interval. The glass transition temperatures of some polymers, such as polyetheretherketone (PEEK), polyethylene (PE) and epoxy as well as their composites, have tested by the new method, compared with the standardized differential scanning calorimeter (DSC) and DMA methods. The results show that the new TTS method is comparable with the existing methods, but has advantages of normalizing the effects of the loading frequency on Tg; eliminating the effect of heating temperature rate on Tg; and being more sensitive.