Highly Exfoliated Poly(Ethylene Terephthalate)/Clay Nanocomposites via Melt Compounding: Effects of Silane Grafting

The ammonium intercalated montmorillonite (A-MMT), especially acid treated montmorillonite (H-S-A-MMT), which experienced silane grafting treatment, exhibited highly exfoliation state in poly(ethylene terephthalate) (PET) matrix. It can be explained that the shear stress was transferred effectively from molten polymer to clay layers during melting processing due to the enhanced polymer-clay interaction by the grafted silane, leading to the slippage and peeling of clay sheets. Furthermore, the equilibrium melting point reduction of highly exfoliated nanocomposite calculated by the Hoffman-Weeks formula exhibited great miscibility between clay and polymer, which was proved by the Nishi-Wang equation.