Experimental investigation of the influence of adding nanotubes on Mode I interlaminar fracture toughness of laminated composites

The influence of adding carbon nanotubes on the mode I interlaminar fracture of glass-fiber-epoxy laminated composite has been experimentally studied. So, the hybrid glass-fiber-epoxy-nanotube laminated composites which have 18 fiber-glass plain-weave layers were manufactured by hand lay-up method. The epoxy resin system is made of Epon828 resin with Epikure F205 as the curing agent. The multi-walled carbon nanotube (MWCNTs) modified with hydroxide (-COOH) is also dispersed into the epoxy system in a 0%, 0.1%, 0.5% and 1% ratio in weight with respect to the matrix. The result of tests shows that adding Carbon nanotubes to glass/epoxy composite could improve the mode I properties of composite. The maximum value of the force (in force-displacement diagram) is in 0.5% sample, with a 24.4% increase respect to neat sample. Moreover, the maximum value of the energy of mode I crack propagation is in 0.5% sample, with a 24.15% increase respect to neat sample.