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Polyrotaxanes (PRs) have attracted significant research attention due to their unique topological structures and high degrees of conformational freedom. Herein, we take advantage of an oligo[2]rotaxane to construct a novel class of dynamically cross‐linked rotaxane network (DCRN) mediated by metal‐coordination. The oligo[2]rotaxane skeleton offers several distinct advantages: In addition to retaining the merits of traditional polymer backbones, the ordered intramolecular motion of the [2]rotaxane motifs introduced dangling chains into the network, thereby enhancing the stretchability of the DCRN. Additionally, the dissociation of host–guest recognition and subsequent sliding motion, along with the breakage of metal‐coordination interactions, represented an integrated energy dissipation pathway to enhance mechanical properties. Moreover, the resulting DCRN demonstrated responsiveness to multiple stimuli and displayed exceptional self‐healing capabilities in a gel state. Upon exposure to PPh3, which induced network deconstruction by breaking the coordinated cross‐linking points, the oligo[2]rotaxane could be recovered, showcasing good recyclability. These findings demonstrate the untapped potential of the oligo[2]rotaxane as a polymer skeleton to develop DCRN and open the door to extend their advanced applications in intelligent mechanically interlocked materials. [ABSTRACT FROM AUTHOR]

The intrinsic conflicts between mechanical performances and processability are main challenges to develop cost‐effective impact‐resistant materials from polymers and their composites. Herein, polyhedral oligomeric silsesquioxanes (POSSs) are integrated as side chains to the polymer backbones. The one‐dimension (1D) rigid topology imposes strong space confinements to realize synergistic interactions among POSS units, reinforcing the correlations among polymer chains. The afforded composites demonstrate unprecedented mechanical properties with ultra‐stretchability, high rate‐dependent strength, superior impact‐resistant capacity as well as feasible processability/recoverability. The hierarchical structures of the hybrid polymers enable the co‐existence of multiple dynamic relaxations that are responsible for fast energy dissipation and high mechanical strengths. The effective synergistic correlation strategy paves a new pathway for the design of advanced cluster‐based materials. [ABSTRACT FROM AUTHOR]

A major challenge in designing self-healing polymeric materials is to combine robust mechanical properties and high healing efficiency. Herein, we report a kind of transparent, hydrogen-bonded polymer complex elastomers with both good mechanical strength and rapid self-healing capability under ambient conditions. Such elastomers were simply fabricated by in situ photoinitiated random copolymerization of acrylic acid (AA) and N -acryloyl-6-aminocaproic acid (A6ACA), in the presence of a linear polyethylene oxide (PEO). By evaporating water molecules from the samples via free drying, the dynamical hydrogen bonding between PEO and poly(A6ACA-co-AA) were substantially formed, which endowed the polymer chains to form physically crosslinked three-dimensional polymer network, as well as the topological chain entanglements. The resulting optically transparent elastomers exhibited both good mechanical strengths (at break) as high as 1.73 MPa, and excellent stretchability that could be stretched up to 24 times their initial length, respectively. Comparing with the elastomers based on PEO and PAA homopolymer without the A6ACA comonomer, the introduction of A6ACA as a comonomer afforded complex elastomers with comparable mechanical strength and, more importantly, significantly improved self-healing efficiency even under ambient conditions, probably due to the significantly decreased glass transition temperature that facilitated chain mobility and reformation of hydrogen bonds. It is therefore believed that the copolymerization strategy offers a practical method to tune the compositions and to tailor the properties of hydrogen-bonded polymer complexes for engineering elastomers with balanced mechanical and self-healing performance under ambient environment for various applications. Image 1 • In situ copolymerization to afford hydrogen bonded polymer complex elastomers. • Feasibly tunable chemical compositions and mechanical properties. • Improved self-healing capacity under ambient conditions. • Providing a practical method to tailor the performance for specific applications. [ABSTRACT FROM AUTHOR]