• Adding an optimum amount of PEI to CNT/PEEK nanocomposites reduces molten viscosity by ~50% while increasing strain to failure by 129% and fracture energy by 97%.
• The direct wet powder blending method using a vertical injection molding machine ensures uniform dispersion of CNT/PEI powder, improving processability without compromising thermal resistance.
• The combination of CNTs and PEI enhances the toughness of PEEK nanocomposites, overcoming the typical trade-off between strength and ductility.
• These improvements facilitate the use of PEEK in thermoplastic composites for demanding applications such as aerospace and automotive.