Viscometric Properties of Binary Liquid Systems: Acetonitrile + Ethanolamine, Acetonitrile + 3-Amino-1-Propanol, and Water + 3-Amino-1-Propanol from 303.15 to 323.15 K

Alkanolamines are essential in industrial gas absorption and CO₂ capture, necessitating a thorough understanding of their transport properties. This study investigates the dynamic viscosities (η) of binary liquid mixtures comprising 3-amino-1-propanol (AP) or ethanolamine (EA) with water (W) or acetonitrile (ACN) across the full composition range and at temperatures spanning 303.15 to 323.15 K. Several derived and excess properties, including deviations in viscosities (Δη), kinematic viscosities (ν), deviations in kinematic viscosities (Δν), and free energies of activation for viscous flow (ΔG^≠) along with their excess (ΔG^≠E), were calculated to elucidate molecular interactions. The experimental data were correlated using various models, including the Jouyban-Acree model and the Redlich-Kister equation. The McAllister four-body model demonstrated the best agreement among the mixing laws considered, outperforming the Ausländer model. New group interaction parameters were determined for CH₂NH₂-CH₃CN, expanding UNIFAC-VISCO’s applicability and demonstrating good predictive capability for ACN + EA and ACN + AP type systems. Distinct differences in molecular interactions were observed between the aqueous (W + AP) and nonaqueous (ACN + AP and ACN + EA) systems, contributing valuable insights into the behavior of alkanolamine mixtures in diverse solvent environments.