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 3 0-60 degrees C using a gravimetric sorption method. Fick's equation wa s used to calculate diffusion coefficients. The activation parameters for diffusion have been obtained from a temperature dependency of diff usion coefficients using the Arrhenius relationship. Concentration pro files of liquids at different penetration depths of the polymer sample s for different times have been obtained both from an analytical solut ion of Fick's equation and by using a numerical method. Experimental s orption results and the computed quantities have been discussed in ter ms of the nature of the penetrant molecules and the morphology of the polymers. (C) 1997 Elsevier Science Ltd.