Volumes of mixing ofn-alkanenitriles withn-alkanes: Interpretation through the Prigogine-Flory-Patterson theory

Abstract

We present in this work the results of measurements of excess volumes of mixing VE at 30°C over the whole composition range for sixteen mixtures of n-hexanenitrile, n-octanenitrile, n-decanenitrile, and n-dodecanenitrile mixed individually with n-heptane, n-decane, n-tridecane, and n-hexadecane. The experimental values of VE show a regular pattern of behavior for the four sets of binary systems. In each group of mixtures for a given n-alkanenitrile, the magnitude of VE decreases as the n-alkane chain-length decreases. For mixtures containing a common n-alkane, VE decreases with increasing n-alkanenitrile chain-length. In order to explain the observed behavior, we have used the Prigogine-Flory-Patterson theory, which divides VE into three different contributions. The agreement between the theoretical and experimental VE is reasonable for the systems studied.