<scp>TPU</scp> Nonwoven Fabrics Enhanced the Erosion Resistance and Interlaminar Fracture Toughness of <scp>CF</scp>/<scp>EP</scp> Composites

ABSTRACT Carbon fiber‐reinforced polymer composites (CFRPs) are extensively employed in engineering applications owing to their exceptional strength‐to‐weight ratio and outstanding fatigue resistance. Nevertheless, when utilized in critical components such as aircraft wings, wind turbine blades, and structural elements, their performance and durability are frequently degraded by harsh environmental conditions. To address these challenges, thermoplastic polyurethane (TPU) nonwoven fabric was introduced as an interlayer in carbon fiber/epoxy (CF/EP) composites to improve both erosion resistance and interlaminar fracture toughness. Experimental investigations revealed remarkable enhancements in mechanical properties: the CF/TPU/EP composites exhibited a 28.6% increase in maximum load, an 11.8% improvement in tensile strength, and a substantial 45.3% augmentation in bending load compared to conventional CF/EP composites. Moreover, the erosion resistance demonstrated progressive enhancement with increasing impact angles (30° to 90°), showing improvements of 58%, 130%, 185%, 227%, and 292%, respectively. These results clearly demonstrate that the TPU‐modified composites achieve superior interlaminar toughness while maintaining excellent mechanical performance. The significant improvements in both mechanical properties and erosion resistance suggest that CF/TPU/EP composites possess considerable potential for demanding applications in aerospace, marine, and construction engineering, particularly under severe service conditions.