TABLE OF CONTENTS R. Kotsilkova
The rheological characterisations of polymer nanocomposites are mostly orientated to better understanding the dynamics of nanoscopically confined polymers [1, 2]. Systematic theological studies of polymer nanocomposites are vital for their process technology, but recent studies on the theology of nanocomposites reported in the literature have been focused mostly on thermoplastic polymer/layered silicate hybrids [1 20]. The rheology of thermoset nanocomposite precursors is still less investigated.
Important factors for the synthesis of polymer/layered silicate nanocomposites are the dispersion of organoclay (intercalation and/or exfoliation) and the interactions between the matrix polymer and the clay surface. In an early publication Krishnamoorti and co-workers [1] reported on the steady shear flow of systems of organo-montmorillonite dispersed in siloxane polymers. Characteristically, the interaction between the organoclay particles and the polymer matrices was found to be weak and the nanoparticles, exfoliated or not, behaved as solid fillers. Furthermore, Krishnamoorti and co-workers [2, 4] studied the flow of 1 10 wt% organoclay nanocomposites based on poly( ?-caprolactone) and polyamide-6, prepared by an in situ polymerisation method. The synthesis process ensured direct bonding between the clay surface and the macromolecules, labelled as an 'end-tethered' structure. Here, the power-law dependence of G' and G" moduli in the terminal zone decreases with the increase of silicate loading, and such non-terminal behaviour is an indication of a pseudo-solid-like response, similar to that of liquid-crystal systems. The non-terminal theological behaviour is related mainly to the active interaction between the polymer...
