Synergistic Physical Properties of Multiphase Nanocomposites with Carbon Nanotubes and Inorganic Particles

摘要

Multiphase epoxy-nanocomposites based on multi-wall carbon nanotubes (MWCNT) and inorganic nanoparticles (TiO_2) were produced. The rheological, electrical and thermo-mechanical properties were investigated in order to reveal informations about the interparticle interactions between the different types of nanoparticles. TEM-investigations reveal altered microstructures for the multiphase nanocomposites (MWCNT plus TiO_2). TiO_2 causes changes in the state of dispersion of MWCNT which can lead to an increase of the rheological parameters (e.g. G'). Due to changes in the formation of the percolated MWCNT network during curing, the electrical conductivity is decreased if the concentration of the non-conductive fillers exceeds a critical value. Additional synergistic effects could be found for the glass transition temperature. The presence of nanoparticles leads to a chemical inactivation of reactive groups of the matrix. Thus, the generated interphase between matrix and nanoparticles exhibits a lower curing degree which results in lower thermo-mechanical properties. For the multiphase systems the glass transition temperature is decreased less, due to an inactivation of the surface of the different types of nanoparticles by a self assembly which leads to a higher curing degree of the interphase.