Solvent Transport Behaviors and Kinetic Modeling of Sulfur Cured and Peroxide Cured NBR / CR / ENR Ternary Elastomeric Composites

The longevity performance of rubber composites used in harsh environmental conditions can be ensured by their molecular transport kinetic behavior through swelling studies. In this study, systematic investigations are carried out on the solvent transport behaviors of novel ternary elastomeric composites comprising varied content of nitrile‐butadiene rubber (NBR), chloroprene rubber (CR), and epoxidized natural rubber (ENR) with a constant 30 phr CB loading. The compatibility of mixing is ensured through their almost equal solubility parameter values. The elastomeric contents of the ternary composites are decided following a simplex centroid mixture design approach of Design of Experiments (DoE). In order to study the effect of curing systems, seven composites were prepared and cured by sulfur and another seven by peroxide curing. Solvent transport behaviors of these developed composites are characterized through swelling experiments carried out at room temperature 27°C using different solvents. By adopting standard empirical and Fickian diffusion models, the baseline parameters such as diffusion, sorption, and permeability coefficients are obtained. The results highlighted that sulfur cured systems swell higher due to less dense and flexible polysulphidic crosslinks, whereas those of peroxide cured systems swell lesser due to high density and rigid radical crosslinks. Furthermore, 10 phr ENR content provides better homogenization of the blend and also offers effective swelling and diffusion resistance to the composite. In kinetic model studies, the best fit is obtained for the Pepas–Sahlin model, which ensures that in all the composites, the transport of solvents is governed mainly by the diffusion‐driven phenomena.