Preparation and properties of acrylonitrile-butadiene copolymer hybrid nanocomposites with organoclays

Acrylonitrile-butadiene rubber (NBR) hybrid nanocomposites with organoclays were prepared by melt mixing, and their properties were compared with those of conventional rubber compounds filled with carbon black and silica. Based on X-ray diffraction and transmission electron microscopy, the NBR nanocomposites obtained were found to form generally an intercalated structure, although they formed an exfoliated structure when the organoclay content was low enough, <2 parts per 100 rubber. The NBR nanocomposite showed a simultaneous improvement in ultimate strength and stiffness, which is generally in a trade-off relation in rubbery materials. A characteristic fracture morphology of 'laminated board-type' was observed for NBR nanocomposites instead of typical 'cross-hatched' morphology in conventional rubber composites. The NBR nanocomposites also showed much higher hysteresis and tension set.