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

• Published in: Composites. Part C, Open access Open access, 2022-10, Vol.9, p.100330, Article 100330
• Main Authors: Ji, Yi, Chen, Yi, Yuan, Bingyan, Hu, Xiaozhi, Qiao, Yingjie
• Format: Article
• Language: English
• Subjects: Capillary action; CNT bridging; Composite repair; Compressive property; Resin pre-coating
• ISSN: 2666-6820; 2666-6820
• DOI: 10.1016/j.jcomc.2022.100330

•Resin Pre-Coating (RPC) mixed CNT is effective for repairing delamination in CFRP.•Sharp delamination tips in CFRP were filled by RPC/CNT through capillary action.•The surface properties of 5% RPC solution have not affected by inclusion of CNT.•CNT has not any chemical effect on the curing process of the resin from RPC.•CNT % in resin from RPC is optimized to achieve better bridging effect. 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. [Display omitted]