Solvent power of solvents for poly(vinyl chloride)

Abstract Osmotic, viscometric, and initial phase separation studies of dilute solutions of poly‐(vinyl chloride) in cyclohexanone, cyclopentanone, tetrahydrofuran, morpholine, nitrobenzene, and tetrahydropyran are reported together with some swelling measurements involving these solvents and dioxane, acetone, and methanol. Values of the polymer–solvent interaction parameter χ 1 obtained from osmotic and swelling measurements suggest the order of solvent power for poly(vinyl chloride) to be cyclohexanone > cyclopentanone > tetrahydrofuran > morpholine > nitrobenzene > tetrahydropyran. A similar order is suggested by the volumes of hexane required to cause initial phase separation. Values of intrinsic viscosity and of the viscosity slope constant k′ give somewhat different orders of solvent power. Reasons for differences in order are considered. The correlation of the volume of hexane required to cause initial phase separation with χ 1 is discussed and it is suggested that the polymer is solvated in solution. Other factors affecting the solvent power of solvents for poly(vinyl chloride) would appear to include the bulk and the solubility parameter of the solvent.