Tensile behaviour of carbon nanotube/polypropylene composite material

The tensile behaviour of the polypropylene (PP) material reinforced by multiwalled carbon nanotubes (MWCNTs) was characterised by mechanical testing. Two different MWCNT weight ratios, namely 2 and 5%, were considered. The strains were measured using strain gauges and a digital image correlation system. The results from mechanical tests were evaluated using scanning electron microscopy (SEM). An increase in the average Young's modulus of 20·29 and 25·19% and in average maximum stress of 26·13 and 33·31% was obtained for the 2 and 5 wt-% MWCNT/PP specimens respectively. The Young's modulus and maximum stress of the MWCTN/PP specimens show a considerable scatter, which is attributed to the varying dispersion and agglomeration size. For specimens with mechanical properties lower than the average values, SEM interpretation revealed poor dispersion and formation of large agglomerations.