TEMPERATURE AND CONCENTRATION-DEPENDENCE OF DIFFUSION-COEFFICIENTS INETHYLENE-PROPYLENE-DIENE COPOLYMERS

Self-diffusion and partition coefficients were measured for two commer cial ethylene-propylene-diene copolymers (EPDM) and five solvents at i nfinite dilution using inverse gas chromatography. Mutual diffusion co efficients for solvents in EPDM also were measured for finite concentr ation using gravimetric sorption for three of the solvents. From the i nverse gas chromatography experimental values for self-diffusion coeff icients were obtained. Free-volume parameters were obtained through re gression of the self-diffusion coefficient as a function of temperatur e. Mutual diffusion coefficients as a function of concentration were p redicted using free volume theory and compared with experimental data obtained using gravimetric sorption. (C) 1998 John Wiley & Sons, Inc.