Strong and Anti‐Impact Polyetherketoneketone Composites With High Loading of Carbon Nanotubes via Co‐Protonation‐Based Pre‐Composition

ABSTRACT

Fiber‐reinforced thermoplastics have great potential as anti‐impact materials, especially polyetherketoneketone (PEKK) with damping properties and carbon nanotube (CNT) with energy dissipation capacity. However, high melt viscosity and poor solubility of PEKK limit its processability, and inter‐tube van der Waals forces lead to CNT agglomeration when used as reinforcement. Therefore, this study developed CNT/PEKK composites by introducing a co‐protonation strategy. Owing to the PEKK dissolvability and the CNT dispersion in superacids, the co‐protonation‐based pre‐composition can be achieved. Meanwhile, the protonation makes it possible to load high‐content CNTs (20 wt%) into composites. The full pre‐composition between CNT and PEKK, complete CNT dispersion, and uniform CNT distribution lead to great performance improvement. The flowability of composite powders promotes the processability and structural stability of hot‐pressed beams. When the content of CNTs reached 10 wt%, the flexural strength and elongation at break of the CNT/PEKK composite beams could reach 294.8 MPa and 10.8%, respectively, and the energy absorption per unit thickness could reach 15.3 J mm ⁻¹ . In addition, the high‐CNT‐content CNT/PEKK composite powders can also be used as masterbatches to develop new materials. Based on these advantages, combined with good electrical conductivity and thermal stability, the CNT/PEKK composites obtained are expected to be used as an anti‐impact material.