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Free keywords:
electron paramagnetic resonance; nuclear magnetic
resonance; polycaprolactone; polymer-clay nanocomposites; spin
labeling; surfactant dynamics
Abstract:
Clays used in polymer-layered silicate nanocomposites are heterogeneous. To improve insight into structure and dynamics of the interface, the iron-free and structurally homogeneous layered silicate magadiite was synthesized. Morphology of the magadiite and the extent of intercalation in melt-prepared composites were characterized by SEM and WAXS. Carbonyl groups in the main chain of the polymer appear to facilitate intercalation. Surfactant motion was studied by 2H NMR and CW EPR. Nanocomposite formation with PCL enhances and microcomposite formation with PS diminishes motion. The activation energies change at the glass transition temperature of PS and the melting temperature of PCL.
