EXCESS POLARIZABILITY AND VOLUME OF MIXING AND THEIR EFFECT ON THE PARTIAL SPECIFIC VOLUME AND THE REFRACTIVE INCREMENT OF POLYMERS IN MIXED-SOLVENTS

The phenomenon of excess polarizability of mixing was confirmed experimentally and justified theoretically. A unified phenomenological method of treatment of changes of thermodynamic properties resulting from mixing was developed and applied to the changes of volume and polarizability. Formulas were developed which related partial specific volume and refractive increment of polymers in mixed solvents with the experimentally observable phenomenological parameters of mixing. The introduction of the parameters related to the excess polarizability of mixing proved crucial for the proper interpretation of refractive increments. The minimum observed on the dependence of specific volume of polymer on the composition of a mixed solvent is a result of the volume changes related to mixing the solvents themselves. © 1979, American Chemical Society. All rights reserved.