Bio-Based Covalent Adaptable Oligorotaxane Networks

The construction of high-performance polymers from sustainable resources represents a forefront direction in materials science. Dynamic covalent chemistry can introduce recyclability into bio-based cross-linked polymers, yet a trade-off between their mechanical robustness and reprocessability often persists. Herein, we report a synergistic integration of biomass feedstocks, dynamic covalent bonds, and mechanically interlocked architectures to create bio-based covalent adaptable oligorotaxane networks (^ORBCANs), seamlessly combining mechanical robustness, biomass-derived sustainability, and circular reprocessability. These networks form through catalyst-free reactions between epoxidized soybean oil and the topologically engineered polyrotaxane. Benefiting from unique force-responsive behaviors of the polyrotaxanes, representative ^ORBCAN-3 exhibits exceptional mechanical properties with significantly enhanced Young's modulus (42 vs. 7.0 MPa), maximum stress (8.6 vs. 2.3 MPa), fracture strain (234% vs. 89%), and toughness (12.6 vs. 1.2 MJ/m³) compared to control whose wheels are nonslidable under applied force. Furthermore, the incorporated β-hydroxy ester linkages enable dynamic transesterification under mild conditions, allowing the material to be efficiently reprocessed multiple times at 110°C while completely retaining its structural integrity and mechanical performance. This strategy bridges biomass-derived platforms and mechanically interlocked architectures, opening a pathway to sustainable polymers with robust mechanical properties, extended durability, and end-of-life recyclability.