Flexible Cages Enable Robust Supramolecular Elastomers

Developing advanced engineering polymers that combine high strength and toughness represents not only a necessary path to excellence but also a major technical challenge. Here for the first time a rigid‐flexible interlocking polymer (RFIP) is reported featuring remarkable mechanical properties, consisting of flexible polyurethane (PU) and rigid polyimide (PI) chains cleverly woven together around the copper(I) ions center. By rationally weaving PI, PU chains, and copper(I) ions, RFIP exhibits ultra‐high strength (twice that of unwoven polymers, 91.4 ± 3.3 MPa), toughness (448.0 ± 14.2 MJ m−3), fatigue resistance (recoverable after 10 000 cyclic stretches), and shape memory properties. Simulation results and characterization analysis together support the correlation between microstructure and macroscopic features, confirming the greater cohesive energy of the interwoven network and providing insights into strengthening toughening mechanisms. The essence of weaving on the atomic and molecular levels is fused to obtain brilliant and valuable mechanical properties, opening new perspectives in designing robust and stable polymers.

Super‐Durable, Tough Shape‐Memory Polymeric Materials Woven from Interlocking Rigid‐Flexible Chains

Xu,

Shao,

Chen

et al. 2024

Boosting the Strength and Toughness of Polymer Blends via Ligand‐Modulated MOFs

Kuang,

Guo,

Guo

et al. 2024

Mechanically robust and tough polymeric materials are in high demand for applications ranging from flexible electronics to aerospace. However, achieving both high toughness and strength in polymers remains a significant challenge due to their inherently contradictory nature. Here, a universal strategy for enhancing the toughness and strength of polymer blends using ligand‐modulated metal–organic framework (MOF) nanoparticles is presented, which are engineered to have adjustable hydrophilicity and lipophilicity by varying the types and ratios of ligands. Molecular dynamics (MD) simulations demonstrate that these nanoparticles can effectively regulate the interfaces between chemically distinct polymers based on their amphiphilicity. Remarkably, a mere 0.1 wt.% of MOF nanoparticles with optimized amphiphilicity (ML‐MOF(5:5)) delivered ≈3.4‐ and ≈34.1‐fold increase in strength and toughness of poly (lactic acid) (PLA)/poly (butylene succinate) (PBS) blend, respectively. Moreover, these amphiphilicity‐tailorable MOF nanoparticles universally enhance the mechanical properties of various polymer blends, such as polypropylene (PP)/polyethylene (PE), PP/polystyrene (PS), PLA/poly (butylene adipate‐co‐terephthalate) (PBAT), and PLA/polycaprolactone (PCL)/PBS. This simple universal method offers significant potential for strengthening and toughening various polymer blends.

Monomer Trapping Synthesis Toward Dynamic Nanoconfinement Self‐healing Eutectogels for Strain Sensing

Lv,

Li,

Yang

et al. 2024

The rapid advancement in attractive platforms such as biomedicine and human‐machine interaction has generated urgent demands for intelligent materials with high strength, flexibility, and self‐healing capabilities. However, existing self‐healing ability materials are challenged by a trade‐off between high strength, low elastic modulus, and healing ability due to the inherent low strength of noncovalent bonding. Here, drawing inspiration from human fibroblasts, a monomer trapping synthesis strategy is presented based on the dissociation and reconfiguration in amphiphilic ionic restrictors (7000‐times volume monomer trapping) to develop a eutectogel. Benefiting from the nanoconfinement and dynamic interfacial interactions, the molecular chain backbone of the formed confined domains is mechanically reinforced while preserving soft movement capabilities. The resulting eutectogels demonstrate superior mechanical properties (1799% and 2753% higher tensile strength and toughness than pure polymerized deep eutectic solvent), excellent self‐healing efficiency (>90%), low tangential modulus (0.367 MPa during the working stage), and the ability to sensitively monitor human activities. This strategy is poised to offer a new perspective for developing high strength, low modulus, and self‐healing wearable electronics tailored to human body motion.