Cure kinetics and physical characterization of epoxy/modified boehmite nanocomposites

Abstract

Nanocomposites based on a cross-linked epoxy matrix with the addition of a reinforcing organically modified boehmite nano-phase were realized and characterized with the aim to produce systems possessing enhanced properties over commercial epoxy systems. Different amounts of a commercially available organically modified boehmite were added to a diglycidyl ether of bisphenol A (DGEBA) epoxy matrix. The rheological characteristic and kinetic behavior of the liquid nano-filled mixtures were analyzed and compared to those displayed by the un-filled resin. A mathematical model was applied to the experimental rheological data in order to assess the aspect ratio of the nano-filler. A proper equation was employed to model the cure kinetics of the nano-filled epoxy systems. The nanocomposites were heat-cured in the presence of an aromatic amine hardener. They were, then, characterized by scanning electron microscopy with EDS analysis, dynamic mechanical thermal analysis, differential scanning calorimetry, and Flexural and Hardness tests. Significant increase in the glass transition temperature, Shore D hardness and maximum flexural strength was found. The experimental results demonstrated the effectiveness of the o-boehmite nano-filler to improve the physical and mechanical properties of the epoxy resin. Further studies are in progress to verify the protective efficiency of the epoxy-boehmite nanocomposite when applied on different substrates as adhesive or coating for construction materials, such as porous stones, concrete, wood, and metal.