Investigating Molecular Interactions in 2‑Ethyl-1-butanol and C₃–C₆ 1‑Alkanols: Thermodynamic and Transport Analysis

This study offers a thorough evaluation of the thermophysical characteristics of 2-ethyl-1-butanol (2E1B) mixed with a series of straight-chain alcohols ranging from 1-propanol to 1-hexanol across 293.15–323.15 K. The work focuses on evaluating the density and viscosity of the above systems. The outcomes reveal that the mixtures exhibit positive deviations in excess molar volume, with a direct correlation with the lengthening of the carbon chain of alkanol. Viscosity deviation is negative from ideal behavior, becoming more pronounced with increasing chain length. This trend suggests the presence of weak intermolecular forces between 2E1B and normal alkanol. Besides, the investigation utilized the Cubic-Plus-Association (CPA) equation to model the binary system density. The equation exhibits a strong correlation with the experimental density, with a maximum discrepancy of only 0.46% observed in the 2E1B + 1-hexanol system. This minimal deviation emphasizes the CPA model’s effectiveness in accurately representing the density measurements.