Influence of blend composition and organic cloisite 15A content in the structure of isobutylene–isoprene rubber/ethylene propylene diene monomer composites for investigation of morphology and mechanical properties

A melt mixing method was used for preparation of immiscible isobutylene–isoprene rubber/ethylene propylene diene monomer blends and their polymer nanocomposites containing cloisite 15A nanoparticles. The morphology of nanocomposites was characterized by Fourier transform infrared spectroscopy and scanning electron microscope techniques. The dispersion of nanoclay in isobutylene–isoprene rubber/ethylene propylene diene monomer blends was studied by transmission electron microscopy and XRD analyses. Curing data of the prepared nanocomposites showed a decrease in scorch time (t₅) and optimum cure time (t₉₀) with increasing nanoclay content. Intercalation of rubber chains into the organoclay silicate layers was specified by d-spacing amount estimated according to the XRD results. Based on XRD results, a leftward shift towards lower diffraction angles in the organoclay characteristic peak was observed, indicating an increase in the d-spacing values in comparison with the pure organoclay. It confirms the intercalation of elastomer chains into the nanoclay galleries. The mechanical properties of the polymer nanocomposite specimens including hardness, fatigue strength, elongation at break, modulus and tensile strength were found to be better with increasing the nanoclay content. Also, resilience of the polymer nanocomposites decreased.