Making a strong adhesion between polyetherketoneketone and carbon nanotube fiber through an electro strategy

Abstract High temperature thermoplastics are gaining popularity due to their superior toughness and durability. For a new member in the polyaryletherketone (PAEK) family, polyetherketoneketone (PEKK) has shown the highest melting temperature, up to 380 °C. Meanwhile, it requires a high temperature to improve the interfacial shear strength (IFSS) between PEKK and a fiber, toward advanced thermoplastic composites. Owing to the strong Joule heating in carbon nanotube (CNT) fibers, a more efficient strategy is designed to enhance the IFSS. Under the electro treatment, the surrounding PEKK starts the melting at the fiber surface, and even impregnates into the CNT assemblies. As a result, the interfacial interaction can be remarkably enhanced. The highest IFSS is up to 80.4 MPa for the electro-treated interface between a CNT fiber and PEKK, higher than the thermal-treated IFSS (52.5 MPa) and that between an aramid fiber and PEKK (59.8 MPa).