Resin precoating solutions containing aminated carbon nanotubes for the improvement of mechanical characteristics and repair behavior of carbon/glass composite laminates

Abstract

The delamination damage of carbon/glass composite laminates was effectively restored using the resin precoating (RPC) technique. This technique addresses the limitations of surface-only repairs by deeply penetrating the epoxy resin into the cracks through the capillary action of ethyl acetate. In this study, aminated carbon nanotubes (MWCNTs-NH₂) were incorporated into RPC, resulting in improved adhesive interface bonding. The repair effect was evaluated through compressive strength tests after 8 days of curing the specimens with varying concentrations of RPC and MWCNTs-NH₂. The impact of laminate thickness on the repair was also examined. Three-point bending and tensile testing were performed before and after repair. After 8 days, the precoat solution containing 10 wt% + 3 wt% RPC + MWCNTs-NH₂ exhibited the best repair effect, with an efficiency of up to 30% compared to the unrepaired condition. Furthermore, the tensile and flexural characteristics were somewhat enhanced after restoration.