Effect of MWCNTs addition, on the mechanical behaviour of FRP composites, by reinforcement grafting and matrix modification

Carbon nanotubes have extraordinary potential for the modification of reinforcements and matrices in fiber-reinforced polymer composites for enhanced mechanical properties. In this study, 12 fiber-reinforced polymer composites were produced with and without the addition of functionalized multi-wall carbon nanotubes using different stacking sequences of E-glass and carbon fabric reinforcements in simple and hybrid configurations. Carbon nanotubes were incorporated into the fiber-reinforced polymer components prior to composite fabrication by: (i) grafting on reinforcements, and (ii) matrix modification by carbon nanotubes. The grafting of carbon nanotubes exhibited a pronounced tensile behaviour with carbon-rich fiber-reinforced polymers, whereas carbon nanotube-modified matrix showed more enhanced flexural behaviour overall. Around 12% increase in tensile strength was observed when the carbon nanotubes were grafted on to the reinforcements compared to respective pristine composites, while around 70% increase in the flexural strength was noticed as compared to the respective pristine composties when carbon nanotube-modified matrix was used.