Interfacial toughening of carbon fiber reinforced polymer (CFRP) matrix composites using graphene oxide containing nanofibers

Çaylan, Cansu
The importance of carbon fiber reinforced polymer (CFRP) composites is increasing day by day in everyday life. While they have great importance owing to their high strength- and stiffness-to-weight ratios, these new materials still have some weak aspects which need to be improved. One of these aspects is ‘delamination’. To increase the delamination resistance, the most promising technique is the one that includes the use of nanofibers because of ease of process and no increase in total weight of composites. Recently, hybrid systems which combine the properties of two or more monolithic materials have attracted considerable attentions. This work focuses on the enhancement of interfacial toughness of CFRP composites using hybrid nanofibers which are graphene oxide containing electrospun nanofibers by using nylon 6 (N6)/polycaprolactone (PCL) polymers with different N6 mass ratios (60, 80, 100 wt %). With this aim, firstly, GO has been synthesized and after that homogeneous distribution of containing different size of GO (GO1: 466 nm, GO2: 230 nm, GO3: 165 nm) along the fiber have been studied. The results showed that N6 containing 2 wt % of GO2 provides the increase of G1c-in and G1c-prop values about 21% and 13% according to reference. Composites containing N6/PCL-60/40 with varying quantities of GO3 nanofibers, G1c values could not be increased because of the deterioration of the synergistic relationship between ‘debonding/fiber bridging’ mechanisms. Highest G1c value was obtained with N6/PCL-80/20 containing 0.5 wt % of GO2 composite with a 26% improvement on the G1c-in and 42% on that of G1c-prop.