Epoxy/alumina nanocomposites of various compositions were prepared by dispersing modified and nonmodified boehmite nanoparticles in diglycidyl ether of bisphenol-A using diethylenetriamine as curing agent. Measurements of the viscosity of the nanodispersions provided information on particle-particle and particle-resin interactions. The structure of the nanocomposites was studied by scanning electron microscopy on fractured samples. Effects of nanoparticles on polymer dynamics was studied in detail by dynamic mechanical thermal analysis and two dielectric techniques, broadband dielectric relaxation spectroscopy and thermally stimulated depolarization currents. Three secondary relaxations, c, b, and x, the segmental a relaxation associated with the glass transition, and an interfacial relaxation, in the order of increasing frequency/decreasing temperature, were observed and studied. A correlation between viscosity (of the nanodispersions), storage modulus, glass transition temperature, real part of dielectric permittivity, and ductility of the nanocomposites was observed.

Nanocomposites, having neat polycyanurate networks (PCN) and modified by polytetramethylene glycol polycyanurate networks (PCN/PTMG) as matrices and montmorillonite (MMT) as filler, were prepared using thermal polymerization, and studied with respect to polymerization kinetics, morphology and in particular, molecular mobility. In order to investigate the influence of the clay modifier and the way of preparation two types of commercial MMT were used, while the mixing was obtained mechanically and by using ultrasound. IR-spectroscopy, Wide Angle X- ray Scattering (WAXS) and dielectric techniques including Dielectric Relaxation Spectroscopy (DRS) and Thermally Stimulated Depolarization Current (TSDC) techniques were used to provide information on polymerization kinetics, morphology and molecular mobility, respectively.

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