Repair of delamination-cracks in CFRP using CNT-containing resin pre-coating solution through capillary action

Abstract

Edge-delamination of carbon fiber reinforced plastics (CFRP) has been successfully repaired using a novel technique named resin pre-coating (RPC). The acetone-diluted resin does not only adhere to the surface but penetrates deeply into sub-surfaces through capillary action. In the current study, Carbon Nanotube (CNT) was tentatively added into RPC to further strengthen the bonding. DSC analysis and FTIR results showed no chemical effect on resin curing through adding CNT. Likewise, using CNT as additives has not changed the surface properties of RPC solution with 5 wt% resin and 95 wt% acetone. Compressive testing was performed to validate the effect of CNT incorporation (with four concentrations: 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%) on RPC repair. The results show that the 5% RPC solution mixing 1.5 wt% of CNT works best with a 22% increase over only RPC in repair effectiveness. SEM revealed CNT bridging at the fracture surface of the RPC/CNT-repaired sample.