Mechanical behaviour of polymeric electrolytes in the glassy and rubber-like regions

The mechanical characteristics (resonant frequency and internal friction) have been measured as a function of temperature in the 100–320 K range for polyethyleneoxide-NaSCN polymeric electrolytes. The mechanical behaviors reveals the presence of a low temperature γ-relaxation, little influenced by the addition of sodium thyocianate and of an αα-relaxation, arising from the segmental motions typical of the glass-rubber like transition region. Moreover, in the temperature region between the γ- and alpha-relaxation, a loss further peak is found. Some information concerning its microscopic origin is obtained by following its behavior as a function of the NaSCN content and comparing the results with the known structure of these polymeric complexes.