Interfacial properties and microstructure of multiwalled carbon nanotubes/epoxy composites

The present research highlighted the interfacial interaction between modified multiwalled carbon nanotubes (MWCNTs) and epoxy systemically. Stress-strain behaviors of MWCNTs/epoxy composites derived from tensile tests were discussed. The relationship among the morphology, microstructure of the composite interface and its mechanical properties were investigated by scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM) and X-ray diffraction (XRD). It was found that MWCNTs with necking ends performed significant roles as reinforcing fillers through investigating stress-strain curves and their corresponding HRTEM images. Moreover, compared the microstructure of modified MWCNTs with the original, it was suggested that the modified MWCNTs with disordered outer and integrated inner layers structure are the main parts in absorbing the load and possess a good interfacial adhesion. The preliminary mechanism on performance of interface interaction was proposed in the form of a simplified schematic diagram describing the process of tensile test.