Author: V.N.S.R. Venkateswararao, P. R. Prasad, K P. Krishna, P. Sandhya and V. A. Rani

DOI: http://doi.org/10.31788/RJC.2026.1939727

Diethyl malonate binary mixtures with 3-methyl-1-butanol, 2-methyl-1-propanol, 2-propanol, and 2-butanol wereevaluated at intervals of 5 K throughout the ester's full composition range from 303.15–318.15 K during a dynamicviscosity and density analysis. In order to summarise the experimental results, viscosity deviations (Δη) and excessGibbs free energy of activation for viscous flow (ΔG*E) were calculated. The results were correlated withtheRedlich–Kister polynomial model to determine fitting parameters and standard deviations. Additionally, several semi-empirical models have been proposed for predicting theoretical viscosities, including Grunberg-Nissan, Heric- Brewer, Katti-Chaudhri, Hind et al., McAllister, Kendall–Monroe, and Frenkel. The Hind et al. and McAllister four- body approaches were the closest to experimental values. In these binary systems, the observed variations are further analysed in relation to intermolecular interactions

Keywords: Dynamic Viscosity, Density, Diethyl Malonate, Molecular Collaboration.