The effect of specific interactions on the sorption equilibrium in the polymer/mixed solvent system

Abstract

AbstractUsing the theory of association equilibria, equations are derived for preferential and total sorption into the coil for a ternary system containing inert liquid A, self‐associating liquid B and polymer C, capable of specific interactions with component B. Due to strong interactions, the assumption of random mixing is not valid for this system. In preceding work differences between experiment and prediction based on the classical Flory‐Huggins equation were formally described by the introduction of a ternary interaction term. For this particular system the ternary term may be interpreted as a consequence of the decrease in the entropy of mixing, caused by strong association of component B. On the contrary, if this component is bound to the polymer at the same time, the ternary term decreases. The equations derived in the paper lead to a reasonable fit with experimental data of the system benzene (A)/alcohol(B)/poly(methyl methacrylate)(C).