Supramolecular polymer networks are transiently cross-linked soft materials that have exceptional material properties such as high toughness, contractility, and recyclability. Previous studies have focused on optimizing their uniaxial mechanical features but did not manage to impart them with biaxial ductility. Here, we develop a set of biaxially ductile supramolecular polymer networks constructed by slow-dissociative, noncovalent cross-linkers. Retarding cross-link dissociation kinetics enables access of glass-like networks, exhibiting both enhanced compressibility and biaxial stretchability. Dynamic dissociation/reassociation of transient cross-linking junctions benefits to address biaxial deformation locking, thus achieving a compressive strength of more than 160 megapascals and a large areal strain up to 10,000%. A universal method of quantifying biaxial mechanical properties for supramolecular networks is also reported. This work enlightens the design and construction of biaxially ductile polymeric materials, holding substantial promise in applications including bioelectronic interfaces, soft robots, and tissue implants.
Wu et al. (Fri,) studied this question.