Excess Molar Enthalpies of 1,2-Propanediol + Alkan-1-ols (C1−C6) and Their Correlations at 298.15 K and Ambient Pressure (81.5 kPa)

Abstract

Excess molar enthalpies, , of 1,2-propanediol + methanol, + ethanol, + propan-1-ol, + butan-1-ol, + pentan-1-ol, and + hexan-1-ol have been measured over the entire range of composition at 298.15 K and ambient pressure (81.5 kPa) using a Parr 1455 solution calorimeter. From the experimental results, the excess partial molar enthalpies, , and excess partial molar enthalpies at infinite dilution, , were calculated. While the excess molar enthalpies are negative for the methanol mixture, those for the ethanol, propan-1-ol, butan-1-ol, pentan-1-ol, and hexan-1-ol mixtures are positive over the entire range of composition of 1,2-propanediol. The values increase as the chain length of the alkan-1-ol is increased. The experimental data were correlated by the Redlich−Kister equation and the two thermodynamics models (Wilson and NRTL).