A Highly Efficient Self‐Healing Elastomer with Unprecedented Mechanical Properties

Abstract

It is highly desirable, although very challenging, to develop self‐healable materials exhibiting both high efficiency in self‐healing and excellent mechanical properties at ambient conditions. Herein, a novel Cu(II)–dimethylglyoxime–urethane‐complex‐based polyurethane elastomer (Cu–DOU–CPU) with synergetic triple dynamic bonds is developed. Cu–DOU–CPU demonstrates the highest reported mechanical performance for self‐healing elastomers at room temperature, with a tensile strength and toughness up to 14.8 MPa and 87.0 MJ m−3, respectively. Meanwhile, the Cu–DOU–CPU spontaneously self‐heals at room temperature with an instant recovered tensile strength of 1.84 MPa and a continuously increased strength up to 13.8 MPa, surpassing the original strength of all other counterparts. Density functional theory calculations reveal that the coordination of Cu(II) plays a critical role in accelerating the reversible dissociation of dimethylglyoxime–urethane, which is important to the excellent performance of the self‐healing elastomer. Application of this technology is demonstrated by a self‐healable and stretchable circuit constructed from Cu–DOU–CPU.

Mechano-responsive hydrogen-bonding array of thermoplastic polyurethane elastomer captures both strength and self-healing

“…According to the Ashby plot of UTS versus self-healing temperature for recently reported elastomers, previous tensile strengths did not exceed 20 MPa without the aid of light or a temperature above 40 °C ( Supplementary Fig. 7 and Supplementary Table 3) 9, [21][22][23][24][34][35][36][37][38][39][40]42,43,47 .…”

“…Herein, we report a self-healing carbonate-type thermoplastic polyurethane (TPU) elastomer with the highest concurrent ultimate tensile strength (UTS) reported to date (43 MPa) for a self-healing "elastomer" that functions at ambient temperature; this TPU even outperforms a commercial TPU used for a footwear component [33][34][35][36][37][38] . Basically, the rich carbonyl groups of the carbonate soft segments form H-bonds.…”

Flourishing Self‐Healing Surface Materials: Recent Progresses and Challenges

“…The coordination bonds, as a kind of special noncovalent bond via metals or metal ion by an adjacent ion or the interaction molecular ligands bond. In recent years, the design and applications of coordination bond at materials interface to realize self‐healing surface have attracted significant attention . The hot spot of self‐healing materials studies based on coordination bonds mainly focus on the molecular structure design and the combination with other covalent bonds at interface.…”

A Transparent, High Refractive, Shape‐Memory, Healable, and Recyclable Phenolic Polyurethane Thermoset: Unexpected Roles of Bromine Substituents and Tertiary Amine Catalysts

“…But as a result of permanent crosslinks, they cannot be reshaped, reprocessed, or rehealed after curing, leading to serious environment pollution and a huge waste of resources 2,3. To solve the problem, an effective strategy has been developed by introducing dynamic covalent bonds into the networks 2–6. Until now, different kinds of dynamic PU thermosets have been reported, which contain reversible bonds like aromatic disulfide exchange,7 Diels–Alder reaction,8 reversible alkoxyamine,9 etc.…”

“…But overall, the dynamic properties in the report still need to be improved further, and the complex effects of substituted groups and catalysts on bond‐exchange process of phenolic urethanes have not yet been revealed thoroughly in the aspect of theory. In addition, it is still a challenge to achieve high mechanical robustness and healing efficiency simultaneously due to the strong hindrance of crosslinks to chain motion and fracture repairing 6,14…”