Interlayer toughening of mode I unidirectional CFRP laminates under the synergistic effect of a modified MWCNTs interpenetrating network

• Published in: Composites communications 2025-01, Vol.53, p.102198, Article 102198
• Main Authors: Ke, Hui, Lai, Jiamei, Li, Yilong, Xue, Xiaomei, Liu, Xiang, Cao, Jin
• Format: Article
• Language: English
• Subjects: CFRP composites; Fracture toughness; Interpenetrating polymer network (IPN); Multi-walled carbon nanotubes; Toughening mechanisms
• ISSN: 2452-2139
• DOI: 10.1016/j.coco.2024.102198

Carbon fiber-reinforced polymer (CFRP) composites are commonly used in structural components because of their favorable mechanical properties. However, their limited interlayer toughness, resulting from their laminated structure and inherent brittleness, restricts their broader range of applications. The study's goal was to make the matrix system stronger by connecting carboxylated multi-walled carbon nanotubes (MWCNTs-C) with polydopamine (PDA) and polyethyleneimine (PEI). A ternary resin system consisting of epoxy resin (EP) and vinyl ester resin (VER) was created. This system has an interpenetrating network (IPN)structure and modified particles, which improves the interlayer toughness of unidirectional CFRP laminates. The modified MWCNTs-C has better surface reactivity, which lets it spread out well inside the IPN structure made by EP and VER. This reduces the "self-filtering effect" of the particles that come into contact with the VARTM process. The incorporation of 1 wt% of modified MWCNTs-C particles leads to a significant 107 % improvement in the Mode I interlaminar fracture toughness of unidirectional CFRP composites with GⅠC,prop value. This suggests that 1 wt% is the optimal amount of particle inclusion. The Mode I interlaminar fracture toughness (GⅠC,prop) of unidirectional CFRP composites goes up by 124 % when IPN structural toughening is added, reaching a value of 1216 J/m2. They found that adding IPN structural toughening to unidirectional CFRP composites raised the Mode I interlaminar fracture toughness (GⅠC,prop) by 124 %, giving it a value of 1216 J/m2. We improved the Mode I interlaminar fracture toughness (GⅠC,prop) of unidirectional carbon fiber reinforced polymer (CFRP) composites by 147 % by adding particle reinforcement and interpenetrating polymer network (IPN) architecture. The highest value recorded was 1340 J/m2. Concurrently, the synergistic toughening process was examined by comparing empirical data and scanning electron microscope pictures. This analysis offers a valuable point of reference for choosing the interlaminar toughening method for carbon fiber-reinforced polymer (CFRP) composites. •Interpenetrating polymer networks (IPN) and inorganic particles collaborate synergistically to toughen.•Polydopamine (PDA) and polyethyleneimine (PEI) co-crosslinked carboxylated multiwall carbon nanotubes(MWCNTs-C).•Increased interlaminar toughness of CFRP laminates under synergistic action.