INFLUENCE OF XYLENE CONCENTRATION AND TEMPERATURE ON THE INTRINSIC PARAMETERS OF PVC IN CYCLOHEXANONE-XYLENE BLENDS

The intrinsic viscosity [eta] and Huggins' constant k' of PVC have bee n derived using flow data obtained from dilute solution in cyclohexano ne and in its blends with xylene at temperatures ranging from 10 to 50 degrees C. Polymer-solvent interaction parameters, KeM and KbetaMbeta are obtained from intrinsic viscosity-temperature relationships sugge sted by Fort et al. (Fort, R. J., Hutchinson, R. J., Moore, W. R. & Mu rphy, M., Polymer, 4 (1963) 35). The intrinsic parameters are used to estimate the dissolution characteristics of PVC in cyclohexanone and i n its blends with xylene. It is found that at ambient temperature a bl end of 1:1 cyclohexanone: xylene is a better solvent for PVC than cycl ohexanone alone. (C) 1998 SCI.