Mechanical properties of NBR/clay nanocomposites by using a novel testing system

NBR/clay nanocomposites are prepared by two different filler types: clay microparticles and clay nanoparticles. The morphology properties of all specimens are explored by XRD and SEM. The mechanical properties are characterized by means of a novel video-controlled method under uniaxial tension. Apart a limited increase in tensile stress at small strains, the ultimate stress at rupture of nanocomposites is much higher than microcomposites. The most dramatic phenomenon is the development of volume strain while the materials are stretched. The nucleation of voids is much more active in composites containing the filler with higher specific surface when the cavitation occurs at the poor interface between the clay platelets and the rubber matrix. In turn, the existence of very diffuse voids hinders the propagation of cracks and retards the rupture process. DMA results reveal that the interfacial action of NBR molecules with layered silicates increases with the degree of intercalation.