Exploring the thermodynamic properties of 2-Methyl-1-butanol and C7-C10 alcohols through CPA modeling and experimental analysis

This paper presents an investigation into the thermodynamic and transport characteristics of 2-methyl-1-butanol and C₇-C₁₀ normal alcohols (1-heptanol to 1-decanol), with a specific focus on their binary mixtures. The experimental analysis encompassed a temperature range of 293.15 to 323.15 K, during which the density and viscosity of these mixtures were measured. The study reveals that all the binary mixtures exhibit positive excess molar volumes, which progressively increase as the alkyl chain length in the alcohols increases. Simultaneously, the observed viscosity deviations consistently display negative values across all the mixtures, becoming more pronounced as the alkyl chain lengthens. This behavior of the mixtures highlights the weak molecular interactions between 2-methyl-1-butanol and alcohols. In conjunction with the experimental work, this study utilizes the Cubic-Plus-Association (CPA) model to establish a correlation between the densities of these binary mixtures. The model demonstrates a satisfactory agreement with the experimental densities, signifying its efficacy in correlating the density behavior of such mixtures. The largest discrepancy between the experimental data and the correlated values from the CPA model was observed in the mixture of 2-methyl-1-butanol with 1-heptanol, amounting to a mere 0.29 %. This minor deviation underscores the correlation of the CPA model in reproducing experimental results.