Recycled carbon fibre mats for interlayer toughening of carbon fibre/epoxy composites

https://www.sciencedirect.com/science/article/pii/S0264127522002921

Exploring routes for the effective use of recycled carbon fibres (rCFs) is critical to close the loop in the life cycle of carbon fibres. This work demonstrated a potential of using rCFs for interlayer toughening of carbon fibre/epoxy composites. Nonwoven mats based on rCFs and commingled rCFs/Polyphenylene-sulfid (PPS) fibres were used to interlay a laminate, aiming to improve the mode-I and mode-II fracture toughness. The experimental results proved significant enhancements in the interlaminar fracture properties upon interleaving, with the rCF/PPS mats exhibiting a more prominent toughening effectiveness than the rCF mats. For example, the maximum increase in mode-I and mode-II fracture initiation energies of the laminates was 51% and 66%, respectively upon interleaving the rCF mats, and 220% and 105%, respectively by adding the rCFs/PPS mats. The fractography analysis proved that the main toughening mechanisms were fibre debonding and pulling-out for the rCF mats and fibre bridging for the commingled rCFs/PPS mats. The differences in the toughening mechanisms resulted in opposite effects of the interlayer/epoxy adhesion to the fracture toughness, i.e. an improved interlayer/epoxy adhesion increased the toughening effectiveness of the rCF mats, but negatively affected the toughening performance of the rCF/PPS mats.

Dong Quan, Ujala Farooq, Guoqun Zhao, Clemens A. Dransfeld, René C. Alderliesten

Dong Quan, Ujala Farooq, Guoqun Zhao, Clemens A. Dransfeld, René C. Alderliesten. (2022), Recycled carbon fibre mats for interlayer toughening of carbon fibre/epoxy composites. Materials & Design 218. Doi.org/10.1016/j.matdes.2022.110671.