Thermoplastic polyurethane (TPU) has become a pivotal engineering material due to its unique combination of elasticity and processability. Recent research has focused on elucidating the structure-property relationship to guide high-performance TPU design. This study innovatively explores the impact of segment sequence length on material performance through a systematic synthesis strategy. Using pre-polymerization and chain extension techniques

we developed a series of hydrazide-based TPU elastomers with identical hard/soft segment ratios but varying sequence lengths. Characterization results reveal that extending the sequence lengths induces two critical structural modifications: enhanced microphase separation between hard and soft domains

and optimized hierarchical hydrogen bonding networks. These structural changes collectively elevate material performance

with long-sequence TPUs exhibiting a 50% increase in tensile strength (from 50 MPa to 80 MPa)

and significantly higher flow temperatures (ΔT >45 °C) compared to short-sequence counterparts. Notably

stress relaxation tests demonstrate that extended sequences increase the relaxation time significantly

indicating superior dimensional stability. The performance enhancements stem from the dual reinforcement mechanism: microphase separation creates robust physical crosslinks while hierarchical hydrogen bonds enable energy dissipation. This sequence engineering approach provides a paradigm shift from traditional composition-focused design to topological structure optimization

offering a viable pathway for developing TPUs that simultaneously satisfy conflicting requirements of mechanical robustness and processing efficiency in industrial applications.