Fragility, stretching parameters and decoupling effect on some supercooled liquids

The dielectric response of the different binary mixtures of 1,2-propanediol and glycerol have been measured in a spectral range covering nine decades of frequency while the temperature varies from room temperature down to the glass transition temperature T-g. The relationship between the fragility, the stretching parameter and the decoupling between the conductivity and the alpha relaxation times measured by their ratio, tau(sigma)/tau(chi), has been analysed and compared to the experimental data on m-toluidine