Interactions in Poly(vinyl chloride) Solutions

Abstract

Molecular weight–intrinsic viscosity relations for poly(vinyl chloride) in five solvents were measured. It was found that the unperturbed dimension of the polymer coil depends on the nature of the solvent. The double cluster integral, β, was computed for this polymer in 35 solvents assuming the statistical segment to be equivalent to the monomeric unit. Subtracting from β the polar interactions, βe, calculated from the theory of Yamakawa, et al., a correlation between βn=β−βe and the solvent solubility parameter δ1 was found to be similar to that of β=βn of nonpolar polymer–solvent systems. It has been found empirically that the data points can be separated into two relations; one for polymer–linear molecule solvents, and the second for polymer–non linear molecule solvents. It was demonstrated that this separation is consistent with the deficiency of the geometric mean rule of intermolecular interactions. This deficiency apparently originates in the “geometry” of the molecules, e.g., as expressed by the branching parameter l12 in the work of Funk and Prausnitz.