dielectric relaxation studies of amides with 2-methoxyethanol and 2- butoxyethanol using time domain reflectometry technique

Research Article
*Kumar, S., Periyasamy, P and Jeevanandham, P
Dielectric relaxation, Time Domain Reflectometry, Bruggeman factor, Kirkwood Correlation factor

Complex dielectric permittivity measurements of amides like Formamide (FA), N-methylformamide (NMF) and N,N-dimethylformamide (DMF) with alcohols such as 2-methoxyethanol (2-ME) and 2-butoxyethanol (2-BE) has been carried out at different concentration in the frequency range of 10MHz to 30GHz using Time Domain Reflectometry (TDR). The least squares fit method has been used to obtain the static dielectric constant (ε0), relaxation time (τ) and Bruggeman factor (fB) for binary mixtures. The Bruggeman plot shows a deviation from linearity. This deviation was attributed to some sort of molecular interaction which may take place between the unlike molecules. The effective Kirkwood correlation factor (geff) and corrective Kirkwood correlation factor (gf) of the mixtures have been determined and discussed to yield information on the structure and dynamics of the mixtures and it confirms the structural formation due to intermolecular interaction between amides with 2-ME and 2-BE. The relaxation time is increasing with increasing chain length of alcohols and is decreasing with increasing amide concentration. The excess static dielectric constant (εE) and excess inverse relaxation time (1/τ)E values are indicates that is a form of hydrogen bonding interaction between the 2-ME and 2-BE with amides systems, for all the mixtures dipoles are slowly rotated. The free energy of activation for relaxation time (ΔFτ) is greater for initial concentration in all the system studied.