Improvement in the mechanical performances of carbon fiber/epoxy composite with addition of nano-(Polyvinyl alcohol) fibers

Nano-Polyvinyl alcohol fibers (nPVA) were fabricated by using the electrospinning technique, whose diameter was about 40–80 nm. After drying completely, nPVA were well dispersed in the epoxy matrix used for carbon fabric (CF) composites. CF/EP composites containing 0.03, 0.05 and 0.1 wt.% of nPVA were characterized by different mechanical tests; tensile, mode-I fracture toughness and tension–tension fatigue tests. The test results showed that at 0.1 wt.% of nPVA content, the mode-I interlaminar fracture toughness for both crack initiation and crack propagation were significantly improved by 65% and 73%, respectively. The fatigue life dramatically increased 10–30 times longer than those of the unmodified composite at high cycle fatigue while the tensile strength slightly increased. The scanning electron microscopy (SEM) observation revealed that nPVA delayed the crack growth in CF/EP composite as well as the onset of matrix crack. Such delay must improve especially endurance of CF/EP composites.