Kinetics of Diffusion of Styrene Monomer Containing Divinyl Benzene through Vulcanized Natural Rubber

Abstract

Diffusion and sorption of styrene monomer containing divinyl benzene as crosslinker through vulcanised natural rubber were studied in a temperature range of 25-45°C. this study is the primary step in the preparation of an interpenetrating network (IPN) based on natural rubber (NR) and polystyrene (PS) by the sequential technique, where NR is swollen in styrene monomer and its crosslinker and initiator, which is then polymerised in situ. The mechanism of diffusion was analysed and was found to follow an anomalous trend. The influence of the nature of crosslinks and crosslinking density of NR on the transport properties was examined. The diffusion coefficient was calculated and was found to be concentration dependent. Arrhenius parameters for diffusion and permeation processes and other thermodynamic parameters of sorption were estimated. The influence of the cure system, the nature of crosslinks, crosslink density, and temperature on the diffusion process were examined in detail. In the presence of crosslinker, the monomer uptake was lowered, whereas an increase in temperature activated the diffusion process. Finally, the experimental sorption results were compared with theoretical predictions.