MOLECULAR MIGRATION OF SOME INDUSTRIAL SOLVENTS INTO FLUOROPOLYMER MEMBRANES

The molecular migration of nine industrial organic liquids into Du Pon t's VITON fluoropolymers has been studied over the temperature interva l 25-60 degrees C. Migration has been studied in terms of sorption and diffusion of liquids into the membrane materials. A gravimetric metho d is used to measure the solvent uptake. From the sorption results, di ffusion coefficients have been calculated using Fick's equation. A num erical method has been employed to calculate the liquid concentration profiles in the polymers. The kinetic rate constants have also been ca lculated from the sorption results. Activation parameters for sorption , diffusion, and permeation have been estimated by a least-squares met hod using the Arrhenius equation. Copyright (C) 1996 Elsevier Science Ltd.