Effective Combination of Carbon Nanotubes and Polyimide to Enhance Interlaminar Properties of Carbon Fiber Reinforced Polyether Ether Ketone Composites

ABSTRACT Carbon fiber‐reinforced polyether ether ketone (CF/PEEK) composites exhibit high toughness, fatigue resistance, and damage tolerance, demonstrating broad application potential in aerospace. However, the high melt viscosity of PEEK poses challenges during composite fabrication. To address this issue, modifiers such as carbon nanotubes (CNT), polyetherimide (PEI), and PEI‐grafted CNT (CNT@PEI) were incorporated into T700 carbon fiber‐reinforced PEEK prepregs. Composites with varying CNT contents were prepared via hot‐pressing, and their impregnation quality, interlaminar fracture toughness, flexural properties, and interlaminar shear strength were systematically evaluated. The results demonstrate that the addition of CNT@PEI significantly enhances resin impregnation efficiency, flexural modulus (up to 121 GPa, +5.2%), interlaminar shear strength (92.65 MPa, +18.2%), and interlaminar fracture toughness. These improvements are attributed to reduced resin viscosity, crack path deflection, and energy dissipation mechanisms induced by CNT@PEI.