Structure And Properties Of Carbon Nanotubes Hybrid Multiscale Composites Manufactured Via RTM

Due to their promising physical properties, carbon nanotubes (CNTs) are a goodcandidate for improving the properties of polymer based composites. In this paper, pristineCNTs and CNTs functionalized with carboxylic acid groups (CNTs-COOH) were dispersedin liquid medium by applying the cavitation effect of ultrasound. The carbon and glass fabricwere impregnated by immersing/sonication and coating treatment to prepare nanocompositepreform. Resin transfer molding (RTM) process were used to fabricate hybrid multiscalecomposites. The dispersion quality of CNTs and the capillary infiltration of CNTs modifiedcontinuous fiber with the epoxy were characterized using optical microscope, conductivitymeasurement, solution experiment, wetting experiment and scanning electron microscopy(SEM) to optimize the processing parameters, respectively. More epoxy is adsorbed by CNTsmodified continuous fiber. It was demonstrated that the interlaminar strength (ILSS) and theflexural strength of the pristine CNTs/glass fabric hybrid composites increased to the peakvalues up to CNTs loading of0.01g/ml and0.005g/ml, respectively. ILSS and flexuralstrength of the CNTs-COOH/glass fabric hybrid multiscale composites attain the maximumvalues at0.01g/ml and0.0067g/ml the level of two types of CNTs. The pristine CNTs andCNTs-COOH loading of0.005g/ml significantly improved ILSS and flexural strength ofcarbon fabric hybrid composites. SEM images indicated that the enhanced mechanicalproperties of the resulting hybrid composites are attributed to the fracture and pull-out ofmore functionalized CNTs from epoxy. The glass transition temperatures (Tg) of the hybridmultiscale composites containing CNTs-COOH determined by dynamic mechanical analysis(DMA) is higher than that of its counterpart containing pristine CNTs.