DILUTE-SOLUTION VISCOMETRIC STUDY OF POLYMER-SOLVENT INTERACTIONS IN POLY(VINYL CHLORIDE) PLASTICIZER SYSTEMS

The intrinsic viscosity, [eta], measurements have been performed on the solutions of a poly(vinyl chloride) (PVC) resin in various plasticizers including the esters of the phthalic and phosphoric acids. A classical Flory equation pertaining to the linear expansion factor of the coiling chain in solution is invoked to translate the [eta] to the polymer-solvent interaction parameter, chi. The results obtained are in agreement with the literature data. The present work is also concerned with the temperature dependence of chi. This information is particularly useful for estimating the lower critical solution temperature, theta(L), as well as comparing the solvent qualities of the plasticizers used. In addition, the present findings are explicable by the equation-of-state theory.