Dielectric relaxation study of hydrogen bonded structures in ethanolamine with diethanolamine using TDR technique

The complex permittivity spectra for ethanolamine-diethanolamine binary mixture have been determined over the frequency range of 10 MHz to 20 GHz using time domain reflectometry (TDR) method in the temperature rang 35 degrees C to 50 degrees C for 11 different concentrations of the system. The present work reveals molecular interaction between same multi-functional groups [-OH and -NH2] of the alkanolamines (ethanolamine and diethanolamine) with different molecular size (carbon chain), on the basis of evaluation the static dielectric constants, relaxation time, the corresponding excess properties, the Redlich-Kister coefficients up to their order and Kirkwood correlation factor of the mixture have been determined. The value of static dielectric constant decreases and relaxation time increases with increasing concentrations of DEA in ETA for all temperatures. The static dielectric constants for the mixture have been fitted with the modified Bruggeman model. (C) 2012 Elsevier B.V. All rights reserved.