The organo-montmorillonite layers are dispersed into
nanometer size particles (Figs. 3 and 4). Single
montmorillonite layers and some multi-layer stacks
(shown as intercalated layers) in the case of EPDM
containing 3.0 phr organoclay are seen in a1 of Fig. 3; it
indicates that exfoliated and partially intercalated
organo-montmorillonite layers coexisted in the directed
blended EPDM/organoclay nanocomposite. On the
contrary, b1 of Fig. 4 clearly reveals many exfoliated
layers and a few layer stacks in the extruded composite.
The a2 of Fig. 3 and b2 of Fig. 4 are the TEM images in a
larger observation scales. The layers of extrusion
nanocomposite dispersed more uniformly and their
diameter is thinner than that of the directed blended
nanocomposite. The difference is due to the higher shear
force during extrusion for extruded nanocomposites.