the role of multi-wall carbon nanotubes on fracture mechanism of epoxy nanocomposite

in order to investigate the role of multi-wall carbon nanotubes (mwcnts) on fracture mechanism of epoxy nanocomposites, a series of tensile standard specimens reinforced with different carbon nanotube contents (0, 0.3, 0.6 and 1 wt%) were produced. the fracture surfaces of the produced nanocomposites were evaluated using scanning electron microscope (sem). the results show that the surface fracture of epoxy nanocomposites comprised of three regions, i.e. mirror, transition and final propagation zones. the extension of all zones depends strongly on curing agent as well asmwcnts content. the mirror zone is disappeared as curing agent and mwcnts content increases, while the transition zone depends on the nucleation rate of secondary microcrack. the pattern of final propagation zone becomes coarser as mwcnts are added to epoxy system.