Thermodynamic Studies of Polyvinyl Acetate Solutions in the Dilute and Moderately Concentrated Range

Abstract

Osmotic pressure measurements on polyvinyl acetate solutions have provided values of the constant μ in methyl ethyl ketone, 1,2,3‐trichloropropane, acetone, dioxane, and dimethyl phthalate. Modifications in techniques have permitted measurements in the first two solvents at different temperatures at concentrations (c) up to 0.07 g/cc. The osmotic pressure can be expressed as a power series in c with three terms; the coefficients of c² and c³ are larger in trichloropropane than in methyl ethyl ketone. The partial molal heats, entropies, and free energies of dilution in these two solvents have been calculated. All are numerically greater for trichloropropane. The heats of dilution are negative; ${\mathrm{\Delta H̄}}_1{\mathrm{/v}}_2^2$ is roughly constant for methyl ethyl ketone but increases somewhat with concentration for trichloropropane. The entropies of dilution are much smaller than those given by the lattice theory.