Mechanochromic Self-Healing Materials with Good Stretchability, Shape Memory Behavior, Cyclability, and Reversibility Based on Multiple Hydrogen Bonds

Abstract

It is challenging to develop materials with roomtemperature self-healing ability and mechanochromic response from mechanical stimuli to optical signals by a facile and simple preparation process. Herein, novel mechanochromic self-healing materials were designed by a simple synthesis procedure, balancing the mechanical properties, self-healing, stretchability, and mechanochromic response. Moreover, we designed and prepared the mechanochromic self-healing materials with different soft and hard segments by introducing multiple hydrogen bonds into the network, improving the mechanical properties and self-healing efficiency. In addition, the optimized sample exhibited good shape memory behavior (shape recovery ratio of 94.4%), self-healing properties (healed by pressing during stretching process), high tensile strength (17.6 MPa), superior stretchability (893%), fast mechanochromic response (strain of 272%), and great cyclic stretchingrelaxing properties (higher than 10 times at strain of 300%). Above all, mechanochromic self-healing materials have promising potential in various fields, such as stress sensing, inkless writing, damage warning, deformation detection, and damage distribution.

Tough and Self-Healing Waterborne Polyurethane Elastomers via Dynamic Hydrogen Bonds Design for Flexible Conductive Substrate Applications

“…The molecular chains at the cracks diffuse and rearrange with each other, forming a new hydrogen bond network structure at the damage. The mechanical performance and repair efficiency of the prepared WTA-X are evidently superior when compared with previously reported self-healing materials (Figure c). – The stress–strain curves of the samples before and after repair are shown in Figure d,e and Supplementary Figures S5–S8. With the increase of the IPDA content, the mechanical properties are gradually improved, which is due to the formation of a large number of urea bonds in the system.…”

A Highly Effective Self-Healing Waterborne Polyurethane Vitrimer Containing Conjugated Schiff Base Bonds Driven by Photothermal

“…After 25 min of exposure to visible light, the film successfully lifted a 7.0 kg bucket of water without breaking (Figure f). After comparing the healing efficiency, healing times, and mechanical strength of the 2-VPSB-WPU polymer with those of reported self-healing polymers (Figure g and Table S4), − it was evident that the mechanical strength of this material was higher in short healing times. Therefore, a balance of highly efficient healing properties and excellent mechanical strength was achieved by the VPSB-WPU vitrimer.…”

Enhancing Dental Material Performance: Tung Oil-Infused Polyurea Microcapsule Coatings for Self-Healing and Antimicrobial Applications

“…Control methodologies for these self-healing mechanisms are engineered specifically for their respective systems. Intrinsic healing is modulated by the physical and chemical properties of the polymer, such as the balance between soft and hard segments, which influences flexibility and self-healing efficiency [15]. In contrast, extrinsic healing is mechanically activated by damage to the material, which necessitates a carefully designed microcapsule shell that remains intact under normal conditions but responds when needed [16].…”