Influence of carbon nanotubes/polyetherketone‐cardo interlayer structure on mode II interlaminar fracture toughness of the interleaved carbon fiber reinforced epoxy composites

Abstract

Delamination is always considered as a threat to the resin matrix composite laminates due to the nonvisibility from the outside. Much effort on the interleaving toughening has been made to improve the interlaminar fracture toughness. The synergistic toughening effect of thermoplastic resin and carbon nanotubes (CNTs) has been the topic in the interleaving toughening. In this study, the influence of the hybrid structure between thermoplastic polyetherketone-cardo (PEK-C) and CNTs on the toughening efficiency was investigated. The mode II interlaminar fracture toughness was tested and the fracture surface was examined by scanning electron microscope. The results showed that the interlaminar structure was closely related with the interlayer structure and the synergistic toughening effect depended greatly on the hybrid structure.

Interlaminar fracture toughness of carbon/epoxy composites laminates toughened by short carbon fiber

“…The specimens with SCF interlaminar toughening showed a small plateau area after the linear zone and before the maximum load. At this stage, plastic deformation occurred and subcritical cracks appeared in the middle of the laminates 16 . As the loading continued, the curve reached the maximum value.…”

“…At this stage, plastic deformation occurred and subcritical cracks appeared in the middle of the laminates. 16 As the loading continued, the curve reached the maximum value. The curves of SCF toughened specimens showed a non-linear decline during the decline differed from the vertical decline of the untoughened specimens, which indicating that the SCF could effectively inhibit the destabilization expansion of cracks.…”

“…[13][14][15] Ma et al reported that pure carbon nanotube films increased the composite mode II IFT by 10.9%. 16 Shin et al investigated the effect of CNT buckypaper as an interlayer toughening material on the fracture toughness of composites made of different forms of carbon fiber prepreg (unidirectional (UD) and woven (WN)), 17 and this study was shown that the addition of buckypaper increased the mode II IFT of UD laminate by about 45.9%. In comparison, it increased the mode II IFT of WN laminates by only 16.6% because the modulus and strength of WN laminates were lower than those of UD laminates.…”

“…Carbon materials such as carbon nanotube (CNT), carbon fiber and graphene are ideal interlaminar toughening materials applied directly or made into films, non‐woven fabrics, etc., to be added to composite interlaminar plies to improve the IFT of composites 13–15 . Ma et al reported that pure carbon nanotube films increased the composite mode II IFT by 10.9% 16 . Shin et al investigated the effect of CNT buckypaper as an interlayer toughening material on the fracture toughness of composites made of different forms of carbon fiber prepreg (unidirectional (UD) and woven (WN)), 17 and this study was shown that the addition of buckypaper increased the mode II IFT of UD laminate by about 45.9%.…”

A New Strategy to Improve the Toughness of Epoxy Thermosets—By Introducing Poly(ether nitrile ketone)s Containing Phthalazinone Structures

“…However, it significantly reduces the strength and modulus of the material [ 8 , 9 ]. Another strategy is incorporating secondary components such as rubbers [ 10 , 11 ], nanoparticles [ 12 , 13 , 14 ], the thermotropic liquid crystalline polymer [ 15 , 16 , 17 ], and thermoplastic resins [ 18 , 19 , 20 , 21 ] into epoxy resins. Unfortunately, adding rubber particles can significantly reduce the system’s modulus and glass transition temperature [ 22 ], and the uneven distribution of nanoparticles can lead to defects in the material [ 23 ].…”