VISCOELASTIC AND DIELECTRIC-RELAXATION STUDIES OF SOME KETONES IN DILUTE-SOLUTIONS OF BENZENE, PARAFFIN OIL AND THEIR MIXTURES

Dielectric parameters of ketones, viz. ethyl methyl ketone, methyl iso butyl ketone and acetophenone have been studied at a fixed microwave f requency of 9.44 Ghz at 30 degrees C in dilute solutions of solvents o f widely different viscosities (eta), prepared by mixing benzene and p araffin oil in different proportions. Dielectric constant (epsilon') a nd loss factor (epsilon '') have been measured as a function of concen tration of the polar molecules in the dilute solutions in non-polar so lvents. It has been observed that the dielectric relaxation time varie s nonlinearly with the solvent viscosity. This nonlinear dependenc has been explained on the basis of the concept of dynamical viscosity (et a) and viscoelastic relaxation process of the medium. The Magee's equ ations have also been used to evaluate the limiting relaxation time (t au') of the polar solutes and the limiting viscosity (eta') of the med ium and it has been observed that the Magee's equations provide reason ably good results for acetophenone and methyl isobutyl ketone but do n ot hold for ethyl methyl ketone.