부산대학교 도서관

Interest in polymeric materials with dispersed nanotubes has increased in recent years. There are several methods to characterize this kind of dispersions that may be based on evaluating the percolation concentration, the 'goodness' of the dispersion, or the matrix-nanotube interphase. Among other techniques, rheology and conductivity are used to this aim. Commonly, the oscillatory rheology measurements are performed within the linear viscoelastic range, which is achieved by operating at small amplitude oscillation shear. Nevertheless, these measurements do not fully describe the behavior of the dispersion structure. In this work, we propose the use of medium amplitude oscillation shear and large amplitude oscillation shear to characterize the dispersion/structure of a thermoplastic polyurethane matrix filled with multiwalled carbon nanotubes. The Ewoldt framework mathematical approach is used to analyze the non-linear stress response. That approach allows obtaining physically grounded magnitudes from the experimental data. These magnitudes allow for a better understanding of the effects of the filler content. [ABSTRACT FROM AUTHOR]