Structure and permeability relationships in polymer nanocomposites containing carbon black and organoclay

Highly anisotropic organoclays and relatively isotropic carbon black particles are both nanoscale fillers widely used to enhance polymer properties. Nanocomposites formed through incorporation of organoclay can result in various morphologies including intercalated and exfoliated structures, while carbon black can also be dispersed in polymeric material and form a network structure. In this study, we illustrate a synergistic effect of having both organoclay and carbon black dispersed in the polymer matrix with different functionality. To evaluate the structure and property (permeability) relationships in these nanocomposites, multi-directional small-angle X-ray scattering (SAXS) and complementary transmission electron microscopy (TEM) measurements were carried out to characterize the organoclay structure and orientation. It was found that the addition of carbon black greatly enhances the tortuosity by the joining of carbon black and organoclays leading to reduced permeability and enhanced barrier properties.