Ionic conduction and structural properties of organic-inorganic composite based on poly(propileneglycol)

Correlation between ionic conduction and structural transition of poly(prop ileneglycol)-silica composite, complexed with lithium salt, was performed b y dc and ac electrical measurements, thermal analysis (DSC) and. nuclear ma gnetic resonance spectroscopy in the 200 to 300 K temperature range. At abo ut 285 K an abrupt increase in-the de conductivity and a change of ac condu ctivity behaviour were observed. Around this temperature it was also observ ed a linewidth narrowing Li-7 NMR while DSC thermograms shows a glass trans ition T-g,immediately followed by a melt point T-m;n The de conductivity-te mperature behaviour was explained by the Vogel-Tamman-Fulcher model and ac by the Random Free Energy Barrier Model.