Extremely Tough, Puncture-Resistant, Transparent, and Photoluminescent Polyurethane Elastomers for Crack Self-Diagnose and Healing Tracking

Abstract

Ensuring material performance reliability and lifetime is crucial for practical operations. Small cracks on the material surface are often detrimental to its safe operation. This study describes the development of a hydrogen bond-rich puncture-resistant polyurethane elastomer with supertoughness. The as-prepared polyurethane transparent films feature high tensile break strength (57.4 MPa) and great toughness (228 MJ m–3). Additionally, a facile, low-cost, crack self-diagnostic approach through photoluminescence using a small luminous pen is reported. The materials efficiently achieved self-healing at 90 °C after the crack formation. The change of fluorescence intensity on the crack can be used to track the self-healing process. Therefore, this work provides a guideline for the material design of supertough, puncture-resistant, transparent, and healable elastomers and a crack self-diagnosis and healing approach.

Healable and Recyclable Elastomers with Record‐High Mechanical Robustness, Unprecedented Crack Tolerance, and Superhigh Elastic Restorability

“…To the best of our knowledge, the healable and recyclable IPDI‐SPU 2000 elastomer exhibits both the highest‐ever tensile strength and the highest‐ever toughness among all the healable polymeric elastomers reported to date (Figure 3b). [ 17,20,21,27,28,40–52 ] The stress–strain behaviors of the IPDI‐SPU 2000 and TDI‐SPU 2000 elastomers, measured at different strain rates, are shown and discussed in Figure S11, Supporting Information.…”

Self‐Healing Functional Electronic Devices

“…[22] In general, the intrinsic selfhealing mode depends on recombining the intrinsic reversible dynamic covalent bonds or reconstructing non-covalent bonds between the cracking interfaces. [31] Reversible dynamic covalent bonds, such as imine bonds, [32] disulfide bonds, [33] acylhydrazone bonds, [34] carbon-carbon double bonds, [35] urea bonds, [36] and so on, possess stronger bond energy than noncovalent bonds, which makes it possible for SHP to realize outstanding mechanical properties and stable self-healing ability. Diels-Alder reaction, disulfide exchange reaction, and transesterification are general methods to developing new materials with dynamic cross-linking property using reversible covalent bonds.…”

Self-healing Materials: A Review of Recent Developments

“…[51] Selfhealing mechanisms are classified into extrinsic and intrinsic. [52] In recent years, it is widely used in the synthesis of elastomer self-healing materials and improvement of mechanical properties and self-healing capability of the selfhealing materials, the advantages of its rapid repair, high material sensitivity and wide application range are remarkable.…”

“…6). Besides, when Hydrogen bond is used as self-healing mechanism by Chen [61] et al, it can also improve the repairing ability of selfhealing materials, which type of silicone rubber may be used in soft robots, wearable electronics and scalable circuit structures.…”