Enhancement of interlaminar fracture toughness of carbon fiber–epoxy composites using polyamide‐6,6 electrospun nanofibers

Abstract

In this study, carbon fiber-epoxy composites are interleaved with electrospun polyamide-6,6 (PA 66) nanofibers to improve their Mode-I fracture toughness. These nanofibers are directly deposited onto carbon fabrics before composite manufacturing via vacuum infusion. Three-point bending, tensile, compression, interlaminar shear strength, Charpy impact, and double cantilever beam tests are performed on the reference and PA 66 interleaved specimens to evaluate the effects of PA 66 nanofibers on the mechanical properties of composites. To investigate the effect of nanofiber areal weight density (AWD), nanointerlayers with various AWD are prepared by changing the electrospinning duration. It is found that the electrospun PA 66 nanofibers are very effective in improving Mode-I toughness and impact resistance, compressive strength, flexural modulus, and strength of the composites. However, these nanofibers cause a decrease in the tensile strength of the composites. The glass-transition temperature of the composites is not affected by the addition of PA 66 nanofibers.

Electrospun nanofibers as reinforcement for composite laminates materials – A review

“…In fact it is not even known if the sample fails for delamination of for matrix/fiber breakage. Similar experiments, such as 3PB or 4PB [21,24,27,28,32,33,57,59,71,72], ILSS [24,32,53,77], and SBSh [21,33,78] have been performed to investigate behaviour of nanomodified composites under bending loads. Areas of interest are the flexural properties of the laminates and the shear stresses occurring between two laminae.…”

Multiscale Polymer Composites: A Review of the Interlaminar Fracture Toughness Improvement

“…The nanocomposites thin film can also be manufactured using electrospinning [194][195][196][197] and electrospun [198][199][200] processes. These methods have gained popularity and are found to be an effective technique to also produce the electrospinning/electrospun nano-interlayers [201][202][203][204][205] which toughen the composite laminate. Klein et al [206] reported the ILFT of specimens (satin woven CFRPs) with carbon nanotube/epoxy films.…”

“…to also produce the electrospinning/electrospun nano-interlayers [201][202][203][204][205] which toughen the composite laminate. Klein et al [206] reported the ILFT of specimens (satin woven CFRPs) with carbon nanotube/epoxy films.…”

Simultaneous enhancement of electrical conductivity and interlaminar shear strength of CF/EP composites through MWCNTs doped thermoplastic polyurethane film interleaves

“…17,18 In recent years, there is an increasing interest in developing interleaving method to improve interlaminar fracture toughness of composite materials. Various thermoplastic polymers, such as polysulfone (PSF), 19,20 polyetherimide (PEI), 21,22 phenoxy, 5,23 and polyamide (PA) 3,[24][25][26][27][28] are introduced into the interlaminar resin enriched regions of laminated composites in the forms of particles, films or nanofiber veils. The toughness against delamination fractures has increased to different extent through ductile deformation, void formation and crazing, and other mechanisms.…”