Dielectric studies of molecular mobility and phase morphology in polymer–layered silicate nanocomposites

Epoxy resin(ER)–smectite clay nanocomposites of exfoliated structure were prepared by dispersing the organically modified smectite clay in the ER and subsequent curing at 75 and 130 °C. Molecular mobility in the nanocomposites was investigated in relation to micromorphology by broadband dielectric relaxation spectroscopy. The large-scale heterogeneity, characteristic of the ER matrix, is suppressed in the nanocomposites and replaced by small-scale heterogeneity related to the presence of the silicate layers. The overall molecular mobility is found to decrease, in general, in the nanocomposites as compared to the ER matrix.