Development of nitrile butadiene rubber–nanoclay composites with epoxidized natural rubber as compatibilizer

The most important factor, which indicates the improvement of properties in rubber by nanoclay, is the distribution in the rubber matrix. The simple mixing of rubber and nanoclay will not exfoliate the filler in the rubbery matrix. Hence, some sort of compatibilizer like epoxidized natural rubber (ENR) can be utilized safely in exfoliating the nanoclay in the matrix polymer. Epoxidized natural rubber and organically modified nanoclay composites (EC) were prepared by solution mixing. The nanoclay employed in this study was Cloisite 20A. The obtained nanocomposites were incorporated in nitrile butadiene rubber (NBR) with sulphur as a curing agent. The morphological study showed the intercalation of nanoclay in ENR and further incorporation of EC in NBR matrix leads to exfoliation of nanoclay. Curing study demonstrated faster scorch time, cure time and increase in maximum torque for the EC incorporated NBR compounds compared to pure NBR. Dynamic mechanical thermal analysis showed increase in storage modulus and lesser damping characteristics for the compounds containing EC loading in NBR matrix. In addition, these particular compounds showed enhancement in overall mechanical properties, higher swelling resistance in oil and solvent and decrease in compression set due to higher reinforcing efficiency of nanoclay in the NBR matrix.