A Dielectric Relaxation Study of Some Liquid Dihydric Alcohols and Their Mixtures with Water

The dielectric relaxation spectrum is measured at 20°C at frequencies up to 72 GHz for the following alcohols and their aqueous mixtures over the whole mixture range: 1,2-ethanediol; 1,2- and 1,3-propanediol; 1,2-, 1,3-, 1,4- and 2,3-butanediol; for comparison moreover: ethanol; diethyleneglycol and 1,2,3-propanediol. It is found possible to analyze the spectra into discrete spectral components according to one and the same scheme in all cases. Three mixture ranges can be distinguished on the volume fraction scale, the parameters of the intermediate and, particularly, the water rich region being rather insensitive to the nature of the alcoholic component.