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 dy namic mechanical analyser (DMA). The principle of this new method is to det ect the change in response of plastic materials to multi-frequency dynamic loading over glass transition interval. The glass transition temperatures o f 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 meth ods. The results show that the new TTS method is comparable with the existi ng methods, but has advantages of normalizing the effects of the loading fr equency on T-g; eliminating the effect of heating temperature rate on T-g; and being more sensitive. (C) 2000 Elsevier Science S.A. All rights reserve d.