Polymer-based clay nanocomposites display rheological properties similar to those of normally particle-filled polymers.The formers’dynamic storage and loss moduli increase with increasing the content of clay at all frequencies and their frequency-dependence exhibits nonterminal behavior at lower frequencies or higher frequencies;further

the storage modulus shows a solidiike plateau at lower frequencies when the content of clay exceeds a critical value.However

the polymer-based clay nanocomposites exhibit nonterminal behavior or solidlike behavior at low content of clay(usually

<10%(wt))

while the normally particle-filled polymers display those behavior at high content of fillers(usually

>40%(wt)).In addition

these rheological features are also dependent upon the aspect ratio

chemistry of clay

structural parameters of polymer matrix and the strength of interactions between polymer matrix and clay.The rheological behavior of polymer-based clay nanocomposites is closely associated with the formation and evolution of their microstructure involved in materials as well as the viscoelastic relaxation processes of polymer chains under specific conditions. The rheological properties and specific viscoelastic relaxation mechanisms of intercalted

delaminated and end-tethered and exfoliated clay/polymer nanocomposites under the external force field were reviewed in this paper.