Transport characteristics of fluoroelastomers by ketones and nitriles

Solvent resistivity and diffusion of the 3M fluoroelastomers, viz. FC-2179 and FLS-2650 have been studied over the temperature interval of 30-60 degrees C using a gravimetric sorption method. Fick's equation was used to calculate diffusion coefficients. The activation parameters for diffusion have been obtained from a temperature dependency of diffusion coefficients using the Arrhenius relationship. Concentration profiles of liquids at different penetration depths of the polymer samples for different times have been obtained both from an analytical solution of Fick's equation and by using a numerical method. Experimental sorption results and the computed quantities have been discussed in terms of the nature of the penetrant molecules and the morphology of the polymers. (C) 1997 Elsevier Science Ltd.