Improving the interlaminar fracture toughness of carbon/epoxy laminates by directly incorporating with porous carbon nanotube buckypaper

In this study, thin carbon nanotube (CNT) buckypapers (BPs) with desired porosity were prepared by using of positive pressure filtration method. The obtained porous BP was then directly incorporated into the middle interface of a composite laminate to improve the interlaminar fracture toughness. Double cantilever beam and end-notch flexure tests were conducted to examine the influence of the obtained BP on mode I and mode II interlaminar fracture toughness (GIC and GIIC) of the laminates. Results have shown the porous BPs would significantly enhance the GIC and GIIC up to 74% and 82%, respectively. Improved interfacial bonding and increased large fracture surfaces were obtained for the laminate incorporated with thin CNT BPs. Similar enhancement was also detected in acoustic emission energy variation for mode II fracture and auxiliary proved the reinforcing effect of the BP.