Influence of Polyethersulfone functionalization on the delamination toughness in carbon fibers composite materials processed by resin transfer moulding (RTM)
Ballout Wael (1)*, Van Velthem Pascal (1), Magnin Delphine (1), Sclavons Michel (1), Pardoen Thomas (2), Bailly Christian (1)
(1) IMCN-BSMA, Université Catholique de Louvain - Louvain-la-Neuve - Belgium, (2) IMMC, Materials and process engineering, Université Catholique de Louvain - Louvain-la-Neuve - Belgium
Composite materials based on carbon fiber/epoxy resin have been widely used in the aeronautical domain for their light weight and their thermomechanical properties. However, these materials possess a low fracture toughness value, which technically limits their application as structural materials. Incorporation of ductile phases like thermoplastics into the epoxy resin is one way to eliminate this problem. In this work, two kinds of high performance polyethersulfone thermoplastics with different end-groups (PES-Cl and PES-OH) are used as tougheners and compared. The determination of the manufacturing parameters is achieved thanks to the study of interdiffusion of PES filaments with RTM6 epoxy resin precursors. The mode I fracture toughness of composite panels with and without PES thermoplastic films is realized by Double Cantilever Beam (DCB) test. Finally, cross-sections and fracture surfaces analysis are performed by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS) to establish links between the observed microstructures and the fracture mechanisms. PES with hydroxyl functionalization gives higher toughness compared to chloride end-groups due to better affinity with RTM6.