Isaías García de la Fuente — Page 3

arXiv2024

Thermodynamics of Mixtures Containing a Strongly Polar Compound. 9. Liquid-Liquid Equilibria for $ε$-CAPROLACTAM + Selected Alkanes

The coexistence curves of the liquid-liquid equilibria (LLE) for systems of -caprolactam with heptane, octane, nonane, decane or 2,2,4-trimethylpentane have been determined by the method of the critical opalescence using a laser scattering technique. All the curves show an upper critical solution temperature (UCST), have a rather horizontal top and their symmetry depends on the size of the alkane. The UCST increases almost linearly with the chain length of the n-alkane. For the octane mixture, the UCST is lower than for the solution including 2,2,4-trimethylpentane.

physics.chem-ph↗

arXiv2024

Thermodynamics of ketone + amine mixtures. I. Volumetric and speed of sound data at (293.15, 298.15, and 303.15) K for 2-propanone + aniline, + N- methylaniline, or + pyridine systems

Densities, $ρ$, and speeds of sound, $u$, of 2-propanone + aniline, + N-methylaniline, or + pyridine systems have been measured at (293.15, 298.15 and 303.15) K and atmospheric pressure using a vibrating tube densimeter and sound analyser Anton Paar model DSA-5000. The $ρ$ and $u$ values were used to calculate excess molar volumes, $V^{E}$, and the excess functions at 298.15 K for the speed of sound, $u^{E}$, the thermal expansion coefficient, $α_{p}^{E}$, and for the isentropic compressibility, $κ_{S}^{E}$ at 298.15 K. $V^{E}$ and $κ_{S}^{E}$ are both negative magnitudes and increase in the same sequence: aniline < N-methylaniline < pyridine. The $V^{E}$ and $κ_{S}^{E}$ curves are shifted towards higher mole fractions of 2-propanone. The data haven interpreted assuming strong acetone-amine interactions, and weak structural effects.

physics.chem-ph↗