Permeation characteristics and modeling of barrier properties of multifunctional rubber nanocomposites

Nanocomposites used in various applications, like tires, diaphragms etc. must exhibit superior gas permeation behavior along with other properties. Oxygen permeability characteristics of such multifunctional styrene butadiene rubber based nanocomposites, including thermodynamics and kinetic aspects of transport have been discussed here. For the first time, these characteristics have been determined for nano, micro and dual filler based multifunctional nanocomposites. The permeability of the nanocomposites was remarkably decreased by the presence of high loadings of montmorillonite due to high aspect ratio and exquisite dispersion, ascertained from morphological studies. The results were explained by the increment in tortuosity and also correlated with the reduction in free volume. Relative permeabilities were compared to predictions of existing permeation models and a novel function was successfully introduced to address deviations. Finally, the enhanced barrier properties of dual filler based nanocomposites have been explained by the formation of zeta potential driven "nano-blocks" and "nano-channels". (C) 2011 Elsevier Ltd. All rights reserved.