Intrinsically Self-Healing Polymers: From Mechanistic Insight to Current Challenges

Abstract

Self-healing materials open new prospects for more sustainable technologies with improved material performance and devices' longevity. We present an overview of the recent developments in the field of intrinsically self-healing polymers, the broad class of materials based mostly on polymers with dynamic covalent and noncovalent bonds. We describe the current models of self-healing mechanisms and discuss several examples of systems with different types of dynamic bonds, from various hydrogen bonds to dynamic covalent bonds. The recent advances indicate that the most intriguing results are obtained on the systems that have combined different types of dynamic bonds. These materials demonstrate high toughness along with a relatively fast self-healing rate. There is a clear trade-off relationship between the rate of self-healing and mechanical modulus of the materials, and we propose design principles of polymers toward surpassing this trade-off. We also discuss various applications of intrinsically self-healing polymers in different technologies and summarize the current challenges in the field. This review intends to provide guidance for the design of intrinsic self-healing polymers with required properties. CONTENTS 4.3.4. Waiting Time 5. Applications of Intrinsically Self-Healing Polymers 5.1. Intrinsic Self-Healing Polymers for Additive Manufacturing 5.2. Intrinsic Self-Healing Polymers for Envelope Applications 5.3. Intrinsic Self-Healing Polymers for Energy Storage 5.4. Intrinsic Self-Healing Polymers for Stretchable Electronics 6. Current Challenges and Future Perspectives 6.1. Trade-off between Self-Healing Kinetics and Mechanical Strength 6.2. Employing Complex Architectures and Combination of Dynamic Bonds to Surpass the Modulus−Self-Healing Rate Trade-off 6.3. Needs for in Situ Analysis of Self-Healing 6.4. Theoretical and Modeling Challenges 7. Conclusions and Outlook Author Information

Influence of Molecular Architecture on the Viscoelastic Properties of Polymers with Phase-Separated Dynamic Bonds

“…One of the potential ways to resolve this problem is design of polymers with reversible (dynamic) bonds. − This will enable much easier recyclability of polymers. Moreover, polymers with dynamic bonds have many properties not available for traditional polymers, including self-healing, shape-memory, and time-programable properties. − Inserting dynamic bonds enables an additional multitude of design parameters targeting unique mechanical and viscoelastic properties. However, understanding detailed molecular mechanisms controlling the viscoelasticity of polymers with dynamic bonds remains a challenge.…”

Renewable lignin and its macromolecule derivatives: an emerging platform toward sustainable electrochemical energy storage

“…5a). The hydrogen bond endowed the hydrogel with a self-healing behavior, 59 and the supercapacitor exhibited a slight capacity retention decline after 5000 cycles. This electrode material realized energy storage via an electrical double-layer behavior (Fig.…”

Self-Healing Binder for High-Voltage Batteries

“…Therefore, inspired by this ability, many self-healing polymers for the repair of microdamage have been produced. These self-healing products can be divided into intrinsic and external types, depending on the need for external agents during the repair. , In external self-healing, a crack in a composite system encounters a nano/microregion containing a crosslinking agent, catalyst, or monomer, and polymerization is then initiated to prevent further development and heal the crack. − However, a potential disadvantage of such an irreversible system is that because of the continuous consumption of the repair agent, the repair time may be limited . In addition, external repair agents include microcapsules or hollow fibers, which increase the mass and occupy significant space in a battery, thereby severely affecting its energy density.…”

“…These selfhealing products can be divided into intrinsic and external types, depending on the need for external agents during the repair. 12,13 In external self-healing, a crack in a composite system encounters a nano/microregion containing a crosslinking agent, catalyst, or monomer, and polymerization is then initiated to prevent further development and heal the crack. 14−18 However, a potential disadvantage of such an irreversible system is that because of the continuous consumption of the repair agent, the repair time may be limited.…”

“…14−18 However, a potential disadvantage of such an irreversible system is that because of the continuous consumption of the repair agent, the repair time may be limited. 12 In addition, external repair agents include microcapsules or hollow fibers, which increase the mass and occupy significant space in a battery, thereby severely affecting its energy density. Traditional repair agents are also commonly incompatible with the internal electrochemical environment of batteries, and this can promote undesired reactions.…”