Morphology development and compatibilization effect in nanoclay filled rubber blends

The present work introduces a new method for the characterization of morphology development and kinetics of nanoclay distribution in hydrogenated acrylonitrile butadiene rubber (HNBR)/natural rubber (NR) blends based on the measurement of electrical conductance during the mixing process. It was found that the online measurable electrical conductance of rubber–clay mixtures, which is originated from the release of the ionic surfactant from the nanoclay galleries during the mixing process depends on two factors: the phase specific localization of nanoclay and the change of the blend morphology. The former is due to the favorable interaction of nanoclay with one of the blend phases whereas the latter is caused by the compatibilization effect of nanoclay. It became obvious that the presence of clay influences the morphology of the blends drastically; a significant change from the co-continuous phase morphology into an island–matrix morphology was observed in HNBR/NR/clay nanocomposites. Thus, the method of the online conductance promises to be a powerful tool to study the nanoclay dispersion processes and to monitor the quality of rubber–nanoclay composites.