TPU ‐g‐ MAH Enhanced Polyester/Polyether TPU Blends for Water‐Resistant Cotton Fabric Bonding

To address interfacial degradation of thermoplastic polyurethane (TPU) adhesives for cotton fabrics during water exposure in applications such as sports footwear and outdoor equipment, a polyester/polyether‐type TPU blending strategy was developed. Maleic anhydride‐grafted TPU (TPU‐g‐MAH) was employed as a compatibilizer to construct a ternary system of polyester‐type TPU/TPU‐g‐MAH/polyether‐type TPU. The compatibilizer promoted hydrogen bonding among hard segments and formed a physical cross‐linked network, facilitating uniform dispersion of polyether segments and improving phase compatibility. This synergistic structure effectively suppressed water penetration and enhanced hydrolytic stability. The optimized formulation (mass ratio: 90/0.5/10) exhibited a tensile strength of 14.58 MPa, elongation at break of 1584%, and T‐peel strength of 12.68 N/mm. After 96 h of water immersion, water absorption was only 1.25%, and the tensile and peel strength retentions reached 91.02% and 88.56%, respectively. These results demonstrate that the TPU‐g‐MAH‐modified polyester/polyether TPU system provides a robust approach to develop water‐resistant, high‐toughness TPUs for textile bonding and outdoor functional materials.