摘要
The inherent trade-off among colloidal stability, reliable mechanical performance under thermal and thermo-oxidative aging, and reprocessability remains a critical bottleneck limiting the broader technological application of waterborne polyurethanes (WPU). Herein, inspired by the concepts of biomimetic artificial foldamers and reversible covalent cross-linking, we demonstrate an WPU system characterized by the synergism of a rigid poly(p-phenylene sulfone amide) based physical network and flexible thioctic acid (TA)-based dynamic S–S network. The strong interactions between PSA segments contribute to ordered H-bonding and π–π stacking, and the sulfone groups contribute to the improved thermal stability and the copolymerization compatibility with WPU. The TA linkages function as supplementary cross-linking and antioxidants, and their flexibility and metathesis reactions provide the kinetic possibility for the adjustment and rearrangement of the PSA network. Well-dispersed dispersion was constructed and produced an excellent elastomer by film formation. In comparison with the controlled blank sample, the dual network exhibited an increase on the tensile strength of 2.4 folds at room temperature, 67 folds at a high temperature of 120 °C, 7.2 folds after 7 days of aging at 120 °C, and 25 folds after three times of reprocessing by thermal pressing. The relatively high elongation at break and good toughness were also largely maintained under all the conditions. The heat deflection temperature increased by 133 °C. The rigid–flexible dual-network WPU, featuring unique environmental friendliness, operation feasibility together with unique thermal robustness, mechanical adaptability, and dynamic network reconfiguration capability represents an effective material platform for the potential high-end use such as high-temperature flexible electronics, stress-buffering components, and reconfigurable elastomeric structures.
危险品化学品经营许可证（带存储）