Dynamic Covalent Bonds in Polymeric Materials

Abstract

Dynamic covalent bonds (DCBs) have received significant attention over the past decade. These are covalent bonds that are capable of exchanging or switching between several molecules. Particular focus has recently been on utilizing these DCBs in polymeric materials. Introduction of DCBs into a polymer material provides it with powerful properties including self‐healing, shape‐memory properties, increased toughness, and ability to relax stresses as well as to change from one macromolecular architecture to another. This Minireview summarizes commonly used powerful DCBs formed by simple, often “click” reactions, and highlights the powerful materials that can result. Challenges and potential future developments are also discussed.

Bioinspired Double‐Dynamic‐Bond Crosslinked Bioadhesive Enables Post‐Wound Closure Care

“…We envision that the bioadhesive with DREAMING functions can be developed by designing an in situ formed adhesive hydrogel via double dynamic bonds crosslinking ( Scheme a). The unique feature of dynamic bonds, reversible breakage and reformation, [ 21 ] was expected to endow the hydrogel with the dissolution and repeatable adhesiveness properties. First, the dynamic bond can be quickly dissociated after imparting the proper external stimuli, [ 21,22 ] which can endow the hydrogel with the on‐demand dissolution property.…”

“…The unique feature of dynamic bonds, reversible breakage and reformation, [ 21 ] was expected to endow the hydrogel with the dissolution and repeatable adhesiveness properties. First, the dynamic bond can be quickly dissociated after imparting the proper external stimuli, [ 21,22 ] which can endow the hydrogel with the on‐demand dissolution property. In addition, when the closed wounds are reopened due to the breakage of the hydrogel by accidental tension, the reformation of the dynamic bond was able to allow the self‐healing of the hydrogel thus repeatedly closing the wounds.…”

“…[ 22 ] Schiff's base bond is a dynamic covalent bond that is widely employed in self‐healing materials. [ 21,23 ] Additionally, the catechol and aldehyde groups used in the formation of these two bonds have been reported to improve the tissue adhesion capacity via multiple non‐covalent and covalent interactions. [ 16,17 ] Rationally introducing these two bonds into a polymer network was inspired by the curing and adhesion process that occurs in mussel glue (Scheme 1b).…”

Covalent Adaptable Network and Self-Healing Materials: Current Trends and Future Prospects in Sustainability

“…While this rapid exchange offers faster self-healing properties, but they often have poor mechanical properties and have low creep resistance [ 5 ]. Dynamic covalent bonds (DCBs) are reversible covalent bonds at elevated temperature but are stable at ambient temperatures [ 6 ]. DCBs network materials are getting more popular because of their dimensional stability, excellent self-healing properties, and their potential as sustainable alternatives for conventional thermosets as well as access to shape memory materials [ 7 , 8 ].…”

Computational Investigation of the Effect of Network Architecture on Mechanical Properties of Dynamically Cross‐Linked Polymer Materials

“…Dynamic covalent linkages are strong and typically stimulus responsive, allowing the resulting materials to be creep resistant. However, they are typically incapable of self‐healing until substantial external stimulus is applied in the form of heat, pH swing, or light . This creates a fundamental trade‐off between dynamic character and stability against creep that cannot be resolved only with one type of dynamic linkage .…”