SORPTION, DESORPTION, RESORPTION, REDESORPTION, AND DIFFUSION OF HALOALKANES INTO POLYMERIC BLEND OF ETHYLENE-PROPYLENE RANDOM COPOLYMER AND ISOTACTIC POLYPROPYLENE

摘要

Molecular transport of haloalkanes into sheets of a polymeric blend of an ethylene-propylene random copolymer and isotactic polypropylene has been studied by a sorption gravimetric technique in the temperature interval of 25-70 degrees C. For all liquids, equilibrium sorption, desorption, resorption, redesorption, and degree of penetrant overshoot have been influenced by the nature of the liquid and the temperature. Diffusion coefficients were calculated from the sorption-desorption kinetic curves using Fick's mathematical relations. The values of diffusion coefficients followed the Arrhenius-type behavior. The temperature-dependent sorption data were analyzed using the van't Hoff relation. The activation parameters for diffusion and heat of sorption data were discussed in terms of the molecular interactions between liquids and the polymer chain segments. The experimental and calculated results are discussed on the basis of the chemical nature of liquids. (C) 1995 John Wiley and Sons, Inc. [References: 15]