A Comprehensive Review of Synthesis, Characterization, and Applications of Additively Manufactured PEKK and PEKK Composites

This review comprehensively examines the synthesis, material characterization, and diverse applications of additively manufactured poly(ether ketone ketone) (PEKK) and its composites. The paper highlights that, through optimized additive manufacturing techniques such as fused filament fabrication (FFF) and selective laser sintering (SLS), PEKK composites can achieve up to 90% of the tensile strength of injection-molded counterparts after post-process annealing. The review details how processing parameters—including nozzle temperature, layer thickness, and build orientation—significantly influence the microstructure, crystallinity, and mechanical behavior of PEKK parts. Incorporation of fillers such as carbon fibers, graphene, and boron carbide further enhances thermal stability, electrical conductivity, and wear resistance, expanding PEKK's suitability for aerospace, biomedical, tribological, and space applications. Notably, PEKK demonstrates exceptional radiation resistance, retaining over 90% mechanical performance after prolonged space exposure, and exhibits high shape recovery ratios (> 90%) in 4D-printed shape memory devices. The review also discusses PEKK's recyclability and circularity potential, as well as current challenges such as achieving consistent filament quality and minimizing porosity. These insights establish PEKK as a versatile, high-performance polymer for advanced engineering and medical applications.