The effect of fullerene C60 on the dielectric behaviour of epoxy resin at low nanofiller loading

Fullerene C-60/epoxy polymer nanocomposites with different C-60 loading (0.0- 0.08 wl.%) have been prepared. Mechanical testing shows that compared with neat epoxy, mechanical and toughening properties of the composites are greatly improved. Dielectric spectroscopy was used to investigate the influence of nanoparticles on the relaxation processes in the polymer matrix. Our study shows that presence of fullerene hampers molecular motions in the epoxy composites that leads to hardening of polymer chains and impedes secondary relaxation processes, which explains the increase of Young's modulus of the nanocomposites. It was found that the activation energy of beta relaxation process decreases for nanocomposites. This finding allows us to confirm the energy-dissipating mechanism that leads to enhanced toughness of nanocomposites. (C) 2014 Elsevier B.V. All rights reserved.