Synergistic Mechanical Reinforcement of Woven Carbon Fiber/Polypropylene Composites Using Plasma Treatment and Nanoclay

Polypropylene (PP) nanocomposite films reinforced with surface-modified nanoclay, maleic anhydride-grafted PP (PP-g-MA), and surfactants, such as cetyl-trimethyl-ammonium bromide (CTAB) and octadecyl-trimethyl-ammonium bromide (ODAB), were fabricated by extrusion, and the effect of surfactant type used for the nanoclay and the take-up speed of extrusion on the mechanical properties and crystallinity of the nanocomposite films were investigated. Multi-scale hybrid composites (MHCs) consisting of plasma-treated plain woven carbon fiber (WCF) and nanocomposite films were manufactured by hot pressing. Flexural and impact tests were performed to measure the mechanical properties at various plasma treatment times. Scanning electron microscopy and X-ray photoelectron spectroscopy (XPS) were used to observe the surface morphology and detect polar functional groups, respectively. Results of XPS analysis showed a considerable increase in the oxygen atomic percentage after plasma treatment. The mechanical properties of the MHCs were greatly affected by the presence of nanoclay in the composite and the plasma treatment. The flexural modulus and strength, impact force, and absorbed impact energy of the MHC specimens treated with plasma (15 s) and reinforced with nanoclay/ODAB(5:1, 1.5 wt%) and PP-g-MA(3 wt%), increased by 69, 87, 49 and 54%, respectively, compared to the neat non-plasma-treated WCF/PP composites.