Interlaminar reinforcement of CF/poly(phthalazinone ether sulfone ketone) thermoplastic composite using ultra-thin films with ultrasonically anchored CNTs on the surface

Carbon fiber reinforced high-performance thermoplastic polymer (CFHPRTP) composites are highly susceptible to interlaminar fracture under external damage, which severely affects the mechanical properties and service life of the composites. In this study, poly(phthalazinone ether sulfone ketone) (PPESK) ultra-thin films with partially exposed carbon nanotubes (CNTs) on their surface were fabricated by an ultrasonic anchoring method, the surface morphology of the resultant ultra-thin films was characterized. The resultant ultra-thin films with surface-anchored CNTs were introduced into the interlayers of carbon fiber reinforced PPESK composites, and the effects of these ultra-thin films on the mode I and mode II interlaminar fracture toughness as well as in-plane properties of the composites have been investigated. The initial and propagation values of composites mode I interlaminar fracture toughness were improved to 1103 J/m² and 1154 J/m², increased by 40% and 33.7%, respectively. Furthermore, the mode II interlaminar fracture toughness was 2076 J/m², with 112% improvement compared with that of the unmodified ones. The flexural strength, flexural modulus, and interlaminar shear strength of the composites increased by 28%, 20%, and 28%, respectively. This study provides a new convenient strategy for interlaminar reinforcement of carbon fiber reinforced thermoplastic polymer composites.