Effect of epoxidation on the transport behaviour and mechanical propertiesof natural rubber

Several modifications of natural rubber (NR) have been tried by Various res earchers and are extensively reported in the Literature. Among these modifi cations, epoxidation has special significance, as it combines several impor tant properties such as oil resistance, low air permeability, strain crysta llising nature and improved damping. The effect of epoxidation on the trans port characteristics and mechanical behaviour of NR has been studied in thi s work. Epoxidised natural rubber (ENR) with 25 and 50 mol% epoxidation lev el (ENR-25 and ENR-50) has been used besides NR. Different transport parame ters such as rate constant, diffusion and permeation coefficients and sorpt ion coefficient have been computed. From the temperature dependence of diff usion, activation parameters were evaluated. A comparison between theoretic al and experimental diffusion results was carried out to understand the mec hanism of diffusion. The polymer network structure in the swollen state has been analysed by applying the affine and phantom models. Mechanical proper ties of unswollen, swollen and deswollen samples were specially investigate d. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.