No abstract

Hybrid clay polymer nanocomposites (CPNs) based on blends of natural rubber (NR) and chloroprene rubber (CR) with different compositions (100/0, 95/5, 90/10, 85/15, 80/20), reinforced with various contents of organomodified montmorillonite (OMMT), were prepared by a two-roll mill via a vulcanization process. Curing data of the prepared compounds indicated a reduction in scorch time (t 5 ) and optimum cure time (t 90 ) with increasing the nanoclay content. Mechanical properties of samples were markedly enhanced upon nanoclay inclusion, due to the proper level of interactions established between nanoclay particles and the rubber matrix as it was evidenced by SEM photomicrographs. Results of X-ray diffraction proved the expansion of the interlayer distance, and transmission electron microscopy micrographs further confirmed that the prepared CPN samples exhibit intercalated/partially exfoliated structures. Moreover, the reinforcement effect of OMMT was reflected in the stress-induced crystallization and network structure of the CPNs based on the rubber-elasticity and tube model theories as well as rheological properties. POLYM. COMPOS., 39:1562-1574

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.

Elastomeric nanocomposites were prepared from carboxylated acrylonitrile butadiene rubber/chloroprene rubber (XNBR/CR), graphene and a glycidyl methacrylate (GMA)-grafted XNBR (XNBR-g-GMA) compatibilizer by using a two-roll mill.

No abstract