Nanocomposites of epoxy resin with graphene nanoplates and exfoliated graphite: Synthesis and electrical properties

Nanocomposites are nowadays one of the most promising materials. Among different fillers, e.g. carbon nanotubes and silicon carbide nanowires (NWSiC), already used with epoxy resin matrices, graphene exfoliated graphite (EG) and graphene nanoplates have some characteristics that make them unique for electromagnetic shielding materials. However, there is still an unresolved problem of proper dispersion that will ensure the homogeneity of samples. To overcome this drawback, inorganic fibres were proposed. An amount of 0.25 phr (parts per hundred; filler content presented as wt.% of the whole polymeric matrix) NWSiC, added to the EG 1 phr/epoxy resin sample, efficiently prevents filler agglomeration. NWSiC were obtained in combustion synthesis and EG was produced from intercalated graphite using microwaves. Finally, nanocomposites with EG from self-propagating high-temperature synthesis were also tested. The properties of the samples have been characterized, revealing an observable improvement of pure resin features. Raw products of combustion synthesis of Si/polytetra-fluoroethylene (PTFE) stoichiometric mixture, carried out in the larger of the presented reactors.