Erosion Resistance and Interfacial Bonding Stability of Nylon 6 Reinforced by Organic Montmorillonite ( <scp>OMMT</scp> ) and Physically Modified Short Bristle Coconut Coir Fibers

ABSTRACT Coir fibers were treated by physical modification (ultrasonic coupled heating treatment) and organic montmorillonite (OMMT) grafting to meet the practical requirements of erosion‐resistant parts for agricultural soil erosion and improve the service performance of polyamide 6 (PA6) composites; OMMT directionally anchors fiber surfaces to fill microcracks and increase interfacial bonding strength. The modified fibers at 3, 5, and 7 wt% were compounded with PA6 and 30% glass fiber‐reinforced PA6 (30% GF + PA6) to clarify the effects of the modification method, matrix type, and fiber loading on the mechanical properties, erosion resistance, and interfacial bonding mechanism. Coir fibers markedly increased hardness, elastic modulus, and tensile strength; the matrix and modification methods dominated the performance and interfacial conditions. The 30% GF + PA6 filled with 7 wt% OMMT‐grafted coir fibers displayed optimal comprehensive performance: the neat matrix exhibited a specific mass loss of 70.19 mg/g, tensile strength of 63.4 MPa, elastic modulus of 1.61 GPa, and hardness of 70.67 HD. By contrast, the composite displayed 67.97 mg/g (3.16% lower), 75.3 MPa (18.77% higher), 2.72 GPa (40.96% higher), 75 HD (6.13% higher). The poor compatibility between the physically modified coir fibers and neat PA6 weakened the erosion resistance. This preparation process should guide the fabrication of high anti‐erosion natural plant fiber composites.