Deformation of Epoxy Nano-Composites

Polymeric materials show properties which come from the interplay of phenomena at various length and time scales. The presence of layered silicates in polymers (PNC) changes the viscoelastic behavior of the unfilled matrix from liquid-like to solid-like because of the formation of a three-dimensional percolating network of exfoliated or intercalated stacks. This gel-like behavior is a direct consequence of the highly anisotropic nature of the nano-clays which prevents their free rotation and the dissipation of stress. Particle to particle interactions is the dominant mechanism in fumed silica nanocomposites whereas particle to polymer interaction is the dominant one in colloidal silica nanocomposites at identical filler concentrations.
Nano clays organically treated were mixed with Epoxy in a high shear mixer. Viscosity, normal stresses and dynamic viscoelastic measurements at various temperatures were determined. Relaxation modulus as function of time at different temperatures was used to get power law fits. Relaxation modulus at different crosslinking level in the nanocomposite shows large difference from nanocomposite with un-crosslinked epoxy. These structures by X-ray diffraction and TEM showed significant exfoliation