Manufacturing and testing of nanocomposites with carbon nanotubes and nanoparticles

Specific manufacturing technologies were applied for the fabrication of epoxy-based nanocomposites with multi-wall carbon nanotubes (MWNT) and nanoparticles (silica and alumina). For dispersing the fillers in the epoxy resin special equipment such as a shear mixer and a high energy sonicator with temperature control were used. The considered filling fraction were, in most cases, 0.1, 0.3 and 0.5 wt%. For MWNT and alumina nanoparticles a higher weight percentage of 3 wt% was also considered. The nanocomposites were subjected to monotonic uniaxial and fracture toughness testing using standardized traction and single-edge notched (SEN) specimens, respectively. SEM analyses were performed to study the fracture surfaces and the effect of fillers on crack propagation. Digital image correlation (DIC) performed using an ARAMIS system made possible the detailed observation of the entire length of each specimen during testing. Only an adequate dispersion of fillers may lead to an increase of the strength and fracture toughness. It was observed that the nanotubes increase the toughness through a crack bridging mechanism which is well-known in the case of standard composites with fibres of μm and mm dimensions. © 2015, Politechnica University of Bucharest. All rights reserved.