Dielectric Relaxation of mixtures of N-methylacetamide and N,N-dimethylformamide solved in benzene using microwave absorption data

Abstract

The dielectric relaxation times T and dipole moments μ of N-methylacetamide (NMA) mixed with N,N-dimethylformamide (DMF) in benzene solutions have been obtained using standard standing wave microwave techniques and Gopala Krishna's single frequency (9.90 GHz) concentration variational method at 25, 30, 35, and 40°C. The energy parameters (ΔH ε, ΔFε, ΔSε) for the dielectric relaxation process of mixtures with equal amounts of NMA and DMF have been calculated and compared with the corresponding energy parameters (ΔHη, ΔFη, ΔSη) for the viscous flow. On the basis of the observations it is found that the dielectric relaxation process can be treated as a rate process like the viscous flow. Solute-solute and solute-solvent types of the molecular associations have been predicted. © 2006 Verlag der Zeitschrift für Naturforschung.