Characterization of Potassium Titanate Whisker and UHMWPE‐reinforced Polyethersulfone/Short Carbon Fiber composites: Mechanical, thermal, and structural insights

Abstract Thermoplastics and their composites have advanced significantly, with ongoing efforts to meet complex engineering demands. This study focuses on polyethersulfone (PES) composites reinforced with 25 wt.% short carbon fibers (SCF), investigating the effects of potassium titanate whiskers (PTW) and ultra‐high‐molecular‐weight polyethylene (UHMWPE) fillers on their properties. Using extrusion and injection molding, PES/SCF composites were developed and modified with 2.5 and 5 wt.% of PTW and UHMWPE fillers. Mechanical tests, including tensile, flexural, and impact assessments, were conducted per ASTM standards. The addition of 25 wt.% SCF improved tensile strength (62.28 MPa) and flexural strength (55.4 MPa), though it decreased notched impact strength (nIS) to 2.1 kJ/m 2 . Incorporating 5 wt.% PTW further enhanced flexural strength (25 MPa) and marginally increased tensile strength (3.61 MPa) but reduced nIS by 0.7 kJ/m 2 . Conversely, 5 wt.% UHMWPE decreased tensile and flexural strengths by 12.07 and 3.4 MPa, respectively, while improving nIS by 1.2 kJ/m 2 . These results suggest that PES/SCF composites tailored with PTW and UHMWPE fillers offer promising potential for secondary structural applications in aerospace and automotive industries, where strength and impact resistance are critical. Highlights PTW and UHMWPE fillers enhance mechanical properties, elevating PES/SCF composite performance for structural use. Thermal analysis (TGA, DSC) confirms increased high‐temperature resilience. SEM imaging shows uniform PTW and UHMWPE distribution, enhancing load transfer and fracture resistance. Higher storage modulus and lower damping indicate enhanced stiffness, durability, and energy dissipation.