Influence of carbon nanoparticles on the polymerization and EMI shielding properties of PU nanocomposite foams

Rigid polyurethane (PU) nanocomposite foams filled with multi-walled carbon nanotubes (MWCNTs), functionalized MWCNTs (f-MWCNTs) and functionalized graphene sheets (FGS) were synthesized by reactive foaming to obtain electromagnetic interference (EMI) shielding materials. Our study indicates that the electrical properties of rigid PU nanocomposite foams are strongly dependent on the foaming evolution, cellular structure and density of these materials, which are themself influenced by the morphology, aspect ratio and surface functionalization of the carbon-based nanofillers. The largest EMI shielding effectiveness was obtained for 0.35 wt% MWCNTs with an electrical conductivity increased of two orders of magnitude ascribed to the formation of a better interconnected network within the systems. © 2014 The Royal Society of Chemistry.