SORPTION AND DIFFUSION OF ALIPHATIC-HYDROCARBONS INTO CROSS-LINKED NATURAL-RUBBER

The sorption and transport of four aliphatic hydrocarbons into natural rubber crosslinked by different vulcanization systems [conventional ( CV), efficient (EV), peroxide (DCP) and a mixed system consisting of s ulfur and peroxide (mixed)] were investigated in the temperature inter val of 28-60 degrees C. Of the four systems, natural rubber vulcanized by DCP exhibited lowest penetrant uptake. It was observed that the ki netics of liquid sorption in every case deviates from the regular Fick ian trend, characteristic of sorption of liquids by rubbers. The diffu sion coefficient, activation energy of sorption, enthalpy, entropy, an d the rubber-solvent interaction parameter were evaluated for the four systems from the swelling data. (C) 1997 John Wiley & Sons, Inc.