MULTISCALE COMPOSITES REINFORCED WITH FUNCTIONALIZED NANOTUBES

摘要

Current manufacturing challenges arising from poor-dispersion and high-viscosityrnsignificantly hinder the realization of potentials that high-performance multifunctionalrnmultiscale composites contain. Especially in fiber-reinforced composite systems, largernintermolecular aggregates formed by Van der Waals forces of carbon nanotubes (CNTs)rncan cause a filtration phenomenon in porous media, which challenges the conventionalrnvacuum-assisted resin transfer molding (VARTM) process. This paper discusses therndevelopment of a functionalized-carbon nanotube (CNT)/fiber-reinforced polymerrncomposite material. Chemical functionalization was performed via oxidization. Oxygencontainingrnfunction groups were found in subsequent oxidized multi-walled carbonrnnanotubes (MWNTs), providing greater reactivity of oxygen-containing groups withrnEPON862/EPI-W than pristine CNTs. This reaction can create the potential to take fulladvantagernof the extraordinary properties of CNTs. A novel vacuum-assisted infusionrnsetup was also applied to incorporate CNTs to enhance the interlaminar length andrnmodulus of composite materials.rnThe enhancement of mechanical properties was remarkable for functionalized multiscalerncomposites when compared with pristine CNT-reinforced composites. Tensile-strengthrnincreased by 15.8% and tensile modulus increased by 27.2%. Moreover, both the shearrnstrength and short-beam modulus increased by 6% and 11.8%, respectively,rndemonstrating improved interlaminar properties. The strain-stress curves also exhibitedrnan increase in toughness. Corresponding SEM data verified improved interfacialrninteractions. CNTs became one part of the cross-linked structure instead of separaternfillers in this hybrid material system. FTIR, RAMAN, DSC and DMA were used torninvestigate the influence of functionalization. Coefficient of thermal expansion (CTE)rnand electrical conductivity of the multiscale composites were also tested.