d-CFRP
Section 1: The use of recycled carbon fibres for the interlayer toughening of carbon fibre/composite.
The enhancement of interlaminar fracture properties of carbon fibre/epoxy composites is critical for their applications in multiple industries. In this work, non-woven mats based on recycled carbon fibres (rCFs) and commingled recycled carbon fibre/PPS fibres (rCF/PPS) were used for interlayer toughening of a carbon fibre/epoxy laminate. The effects of the forms and areal densities of the mats and the adhesion at the interlayer/epoxy interface on the mode-I and mode-II fracture toughness of the laminates were investigated.This experimental study revealed that UV-treated rCF mats and commingled rCF/PPS mats are attracting candidates for interlayer toughening of carbon fibre composites. In particular, the potential for developing tough carbon fibre laminates by interleaving rCFs has been demonstrated.
Section 2: Interlaminar and intralaminar fracture properties of recycled carbon fibre/PPS composites with improved fibre/matrix adhesion.
The development of recycled carbon fibre composites with improved mechanical properties is desirable for expanding their applications. In this work, the interlaminar and intralaminar fracture properties of composite panels manufactured by commingled rCF/PPS non-woven mats were studied. A UV-treatment method was proposed to treat the surfaces of the commingled rCF/PPS mats, that managed to improve the adhesion between the rCFs and the PPS matrix. The experimental results showed that this technique can effectively improve the mechanical properties and intralaminar fracture toughness of the recycled composites. However, a slight decrease in the interlaminar fracture properties was also observed.
Section 3: The adhesive joining of aerospace thermoplastic composites.
Carbon fibre reinforced PEEK and PPS composites are currently the most widely used TPCs for advanced aerospace applications, due to their exceptional mechanical properties, excellent fracture toughness, outstanding thermal and chemical stabilities. However, they possess low surface activities and hence are difficult to be adhesively bonded. This study proposed a high-power UV-irradiation technique to active the surfaces of the PEEK and PPS composites, and successfully obtained their adhesive joints with high structural integrity.
(Note: This is an additional section of work for the d-CFRPs project, that was added to lower the risks arising from the influences of the Covid-19 pandemic. It was carried out in close collaboration with researchers from University College Dublin, Henkel and Shandong University etc.)
