Molecular interaction studies of isopropyl acetate-xylene mixture using dielectric relaxation approach

Abstract

Dielectric relaxation parameters of Isopropyl acetate (IPA)-xylene mixtures with different concentrations and temperatures have been measured in the frequency range of 10 MHz to 30 GHz using time domain reflectometry technique. Static dielectric constant, relaxation time, excess permittivity, excess relaxation time, Bruggeman factor, Kirkwood correlation factor and thermodynamic parameters have been determined to understand molecular association between the IPA and xylene molecules. For entire concentrations of IPA-xylene mixture the Kirkwood correlation factor is less than one which shows the antiparallel nature of electric dipole orientation. The experimental values of dielectric constant obtained from time domain reflectometry are in well agreement with theoretical values of dielectric constant obtained by Luzar model. Positive values of enthalpy and entropy indicating that the system is endothermic and less ordered while Gibbs free energy decreases with increase of IPA in xylene.