Comparative study of mechanical properties and thermally activated shape memory behavior in nanocarbon-reinforced epoxy composites

Purpose This research will produce and define high-performance carbon fiber-reinforced epoxy composites, as well as to improve the multifunctionality of the same by adding conductive nanofillers, namely, the multi-walled carbon nanotubes (MWCNTs) and graphene. This study aims to enhance the mechanical strength, interfacial bonding, conductivity and thermally activated shape memory performance to achieve high performance in structural and smart material applications. Design/methodology/approach The pure carbon fiber-epoxy laminates were produced as control samples and then the hybrid nano composition formulations were made by dispersing the MWCNTs and the graphene at an optimal loading of 0.4 Wt.% into the epoxy polymer through controlled mixing methods to achieve uniform dispersion. The tensile and flexural tests were used to determine the mechanical properties of stiffness and strength. The shape memory behavior was studied under thermal activation, measurement of recovery ratio and recovery time. To analyze the synergistic performance of the fiber reinforcement and nanofiller introduction into the composites, a comparative study was done. Findings Carbon fibers have a notable positive effect on loading capacity and rigidity of the epoxy matrix, whereas nanofillers helped to increase interfacial bonding, the effect of stress transfer and conductivity. Hybrid composites had better tensile and flexural characteristics than pure systems. Moreover, it showed a higher recovery ratio and lower recovery time, as well as faster thermal responsiveness and shape recovery behaviors when compared to the control group of nano-fillers that became conductive. The multifunctional performance improved significantly because of the combined reinforcement strategy. Originality/value This study offers a systematic study of hybrid carbon fiber-MWCNT-graphene epoxy composites that are able to optimize both structural and smart behavior. The proposed system has provided a promising aerospace, automotive and adaptive structural material platform that is not only highly mechanically robust, as is the case with conventional carbon fiber composites but also has the ability to combine the mechanical strength of a material with improved electrical and shape memory capabilities.