Density, Speed of Sound, Viscosity, Excess Properties and Intermolecular Interaction of Methyl tert-Butyl Ether (1) + Isopropanol (2) at 0.1 MPa and (293.15–313.15) K

This study investigates the density, speed of sound, viscosity, and excess properties of the binary mixture of Methyl tert-Butyl Ether (MTBE) and Isopropanol (IPA) at 0.1 MPa and various temperatures (293.15–313.15) K. These properties were measured across a range of temperatures to examine the thermodynamic behavior and molecular interactions in the MTBE–IPA system. Excess molar volumes, isentropic compressibility deviations, viscosity deviations, and free energy for activation for viscous flow were calculated to analyze the nature and extent of molecular interactions between MTBE and IPA. The results reveal notable deviations in excess properties, indicative of specific intermolecular forces, such as hydrogen bonding and van der Waals interactions, which govern the mixture’s behavior. Quantum mechanical calculations and analysis of weak interactions demonstrate that MTBE molecules primarily engage in van der Waals interactions, while IPA molecules form strong hydrogen bonds. Intermolecular interactions in the MTBE–IPA binary system exhibit characteristics intermediate between these two interaction types. This research provides valuable insights for applications in solvent formulation, chemical processing, and environmental science, where MTBE and IPA mixtures are commonly used.