Sorption, diffusion, and permeation of esters, aldehydes, ketones, and aromatic liquids into tetrafluoroethylene/propylene at 30, 40, and 50 degrees C

摘要

The coefficients of sorption, diffusion, and permeation for five organic esters, three aldehydes, one cyclic ketone, and three substituted aromatic liquids have been calculated for tetrafluoroethylene/propylene copolymer membranes at 30, 40, and 50degreesC with the sorption-gravimetric technique. With the sorption data, the concentration-independent diffusion coefficients have been calculated from Fick's diffusion equation. Analytical solutions of Fick's equation under suitable boundary conditions have been obtained so that the liquid concentration profiles in the polymeric membranes at different times and different depths of liquid penetration could be computed. Because of the linearly increasing trend of the diffusion coefficients with temperature, efforts have been made to estimate Arrhenius parameters. Experimental values and the computed quantities have been used to determine the membrane-solvent interactions and to propose suitable applications for the membranes under investigation in various situations. (C) 2003 Wiley Periodicals, Inc. [References: 17]