Slurry‐Processed Carbon Fiber/PEEK Prepregs with Enhanced Mechanical and Viscoelastic Properties

Abstract A stable slurry was formulated by dissolving polyether ether ketone (PEEK) polymer in an organic solvent, p ‐chlorophenol, which was subsequently utilized for the fabrication of carbon fiber (CF) / PEEK prepreg. The CF/PEEK prepregs were successfully prepared using both‐hot melts and slurry‐based processing methods. UV–vis and FTIR spectroscopic measurements were employed to examine the chemical interactions between carbon fibers and PEEK polymer. Cross‐sectional (edge view) SEM images clearly indicate that the PEEK polymer was effectively impregnated into woven carbon fibers, forming a strong interpenetrating network structure in the C‐PEEK‐S prepreg, while it is categorically absent in C‐PEEK‐M, and the surface morphologies (PEEK, C‐PEEK‐M, and C‐PEEK‐S) are nearly the same. The mechanical properties of the CF/PEEK prepreg were significantly compared to those of pure PEEK. The tensile strength and moduli (modulus) of the CF‐PEEK have increased to 71% and 83%, respectively, as compared to pure PEEK. The rheological properties, such as storage modulus, loss modulus, and complex viscosity, have been effectively enhanced. The glass transition temperature ( T g ) has increased to 150 °C for C‐PEEK‐S, which is significantly higher than PEEK ( T g = 134 °C). The storage (Gʹ) and loss modulus (Gʺ) of CF/PEEK prepregs are 1146 and 19.8 MPa, respectively, which are 40% (Gʹ) and 43% (Gʺ) higher than pure PEEK (Gʹ = 818 MPa, Gʺ = 13.8 MPa) at the same temperature (30 °C).