VISCOSITY-TEMPERATURE RELATIONSHIP OF DILUTE-SOLUTION OF POLY(VINYL CHLORIDE) IN CYCLOHEXANONE AND IN ITS BLENDS WITH XYLENE

Absolute viscosities of dilute solutions of poly(vinyl chloride) (PVC) in cyclohexanone and in its blends with xylene were determined at tem peratures ranging from 5 to 50 degrees C and in THF at 5-30 degrees C. The simple Arrhenius reaction kinetics equation, used by Anrade to an alyze the viscosity data of liquids and later by Moore for dilute poly mer solutions, was used to estimate the thermodynamic parameters for t he flow of PVC solutions and the quality of solvents. This relationshi p was also used to calculate thermodynamic parameters for PVC in binar y solvent systems. The data of the activation energy of the viscous fl ow and preexponential factor were further analyzed by using the empiri cal relationships suggested by Moore for flexible polymer chains. The parameters obtained from these relationships are used to estimate and compare the solvency power of solvents and solvent blends. A blend of 1 : 1 cyclohexanone and xylene is found to have better dissolution cha racteristics for PVC than have cyclohexanone and other blends. (C) 199 7 John Wiley & Sons, Inc.