Density, Speed of Sound, Refractive Index, and Viscosity of the Binary Mixtures of N,N-dimethylacetamide with Methanol and Ethanol

Abstract

The thermophysical behavior of the binary mixtures N,Ndimethylacetamide + methanol and N,N-dimethylacetamide + ethanol has been studied through the measurement of density, ρ, speed of sound, u, refractive index, n D , and kinematic viscosity, ν, over the entire mole fraction range at the temperatures of 283.15, 298.15 and 313.15 K and at p = 99.0 kPa. Excess volumes, V E , excess isentropic compressibilities,κ S E , refractive index deviations, Δn D , and viscosity deviations, Δη, were also calculated and correlated with the Redlich−Kister equation. Both systems present negative excess volumes and excess isentropic compressibilities and positive refractive index deviations in the whole composition range. The viscosity deviations are positive for N,N-dimethylacetamide + methanol and turn to negative for N,N-dimethylacetamide + ethanol. Moreover, both systems behave differently when temperature is raised. The experimental results were interpreted based on strength of specific interactions, size, and shape of molecules.

Thermophysical study of the binary mixtures of N,N-dimethylacetamide with 2-propanol and 2-butanol

“…Further it is observed that ΔnD values decrease when temperature increases for both systems, which suggests that the light propagates faster. Based on our previous results [11], it can be seen that mixtures containing lower alkanols give more positive ΔnD values than those containing higher chain alkanols.…”

“…Obviously, all these factors are responsible of final balance between positive and negative contributions. The comparison of excess molar volumes of the binary systems containing higher chain alkanols with lower alkanols taken from our previous results [11], shows less negative V E values. According to several authors [37,38], the higher alkanols possess less proton-donating ability than the lower ones, and therefore heteroassociation effects are smaller in their mixtures, and V E values tend to shift towards positive values.…”

Thermophysical study of the binary mixtures of N , N -dimethylacetamide with 1-propanol and 1-butanol

“…The comparison of excess molar volumes of the binary systems containing higher chain alkanols with lower alkanols taken from our previous results [11], shows less negative V E values. According to several authors [37,38], the higher alkanols possess less proton-donating ability than the lower ones, and therefore heteroassociation effects are smaller in their mixtures, and V E values tend to shift towards positive values.…”

“…Ritzoulis and Fidantsi [5] reported refractive indices at T = 298. 15 Based on our previous results [11], it can be seen that mixtures containing lower alkanols give more positive ΔnD values than those containing higher chain alkanols.…”

“…15 K [8], and phase equilibrium for the 1-propanol and N,Ndimethylacetamide mixture (solid-liquid equilibrium [9] and vapour-liquid equilibrium [10]). An earlier study was undertaken [11], to gain thermophysical information about the N,N-dimethylacetamide when it is mixed with methanol or ethanol. We continue this study, by reporting the experimental density, speed of sound, refractive index and viscosity for the binary mixtures of N,N-dimethylacetamide with 1-propanol and 1butanol at temperatures (283.15, 298.15 and 313.15) K and at atmospheric pressure, p = 0.1 MPa.…”