Synergistic molecular design of key components to address the performance trade-off challenge in bio-based polyurethanes

Abstract

The widespread adoption of bio-based polyurethanes is frequently hampered by the inherent trade-off among mechanical strength, thermal stability, and environmental durability, a common challenge in sustainable polymer design. To address this fundamental challenge, a synergistic molecular design of the key polymer constituents was innovatively implemented in this study. A simultaneous enhancement of all three properties was achieved through the concurrent incorporation of the rigid ring structure of isosorbide (ISO) and the inorganic Si–O framework from (3-aminopropyl) triethoxysilane (APTES) into a castor oil-based polyurethane network. The synergistically modified polymer exhibits a tensile strength of 26.87 MPa, an increased thermal decomposition temperature reaching up to 324 °C, and a distinctly altered degradation profile. Molecular simulations revealed the three-tier mechanisms of this biobased polyurethane material: (1) the rigid ISO skeleton promotes ordered packing and bond localization; (2) the APTES constructs a Si–O network that provides a thermally stable backbone; (3) the dynamic hydrogen-bonding network facilitates excellent energy dissipation. This work successfully circumvents the performance trade-off prevalent in polymer materials through synergistic molecular design, providing a novel design strategy and critical insights for the fabrication of high-performance bio-based polyurethanes. The proposed synergistic enhancement approach pioneers a new technical pathway for the design of high-performance polymers.