Electrical, rheological and mechanical characterization of multiscale composite materials based on poly(etherimide)/short glass fibers/multiwalled carbon nanotubes

Composites based on poly(etherimide) matrix (PEI) with nanoscale reinforcements (multiwalled carbon nanotubes (MWCNTs)) and multiscale reinforcements (MWCNTs and Glass Fibers (GFs)) are processed by melt blending. For nanocomposite materials, we demonstrate that addition of MWCNTs (i) significantly improve electrical conductivity of PEI matrix, (ii) do not significantly improve the mechanical properties (young and flexural modulus) but strongly degrades the strain at break. In the case of multiscale composite materials PEI_GF_MWCNT, strain at break increases with the nanofiller content, and the electrical properties are the same than that in the case of nanocomposites. TEM observations are performed at the PEI/GF interfaces and clearly show a preferential location and orientation of MWCNTs along and perpendicularly to the GFs which explain the evolution of the strain at break for the multiscale composite materials.