Cross‐Linked but Self‐Healing and Entirely Degradable Poly‐Schiff Base Metal Complex Materials for Potential Anti‐Biofouling

Abstract

very desirable to extend their lifespan and be considered as materials derived from renewable resources. [4] The initial report on self-healing materials came from White et al. [5] They designed an encapsulating monomer that was released after cracks broke the capsule and then polymerized within the cracks after mixed with an initiator/catalyst embedded in the matrix.Currently, intrinsic self-healing polymers embedded with reversible dissociation of chemical bonds have become the mainstream of development and are widely used in the research of artificial skin, conductive elastomers, and soft robots. [6] Two approaches, typically, have been employed to construct such self-healing systems, one of which involves the use of noncovalent bonds. What has been widely studied is a macroscopic self-healing system using hydrogen bonding, [7] π-π stacking, [8] and hydrophobic interaction, [9] which includes high repeatability and reactivity of the repair reaction. The second approach relies on dynamic (reversible) covalent bonds, which mainly include systems based on reversible Diels-Alder reactions, [10] reversible reactions of imine moieties, [11] metal ion-ligand binding system, [4a] disulfide exchanges, and radical reshufflings of trithiocarbonates. [12] This self-healing system may potentially provide materials with higher stability and higher mechanical strength.The cross-linked structure is usually designed and embedded in the self-healing polymer system to retain their shape and to improve the mechanical strength of the material. [7a] So far, the main method reported to form cross-linked structures is to incorporate multifunctional reactive monomers into polymer systems [13] or to create metal ion-ligand coordination between molecular chains. [14] However, the employment of multifunctional reactive monomers or macromolecular segments so far usually results in difficult or incomplete degradation, which places a heavy burden on the natural environment, especially in marine ecosystems. [13,15] We conceive herein a design concept that uses the reversible bond of the imine part, the metal ion-imine ligand coordination, and the crystallites to jointly adjust the type and strength of the cross-linking structure to achieve cross-linking, high stretchability, self-healing, and complete degradability. Notably, previous work involving the metalligand interaction of self-healing materials either relied on the Environmentally friendly materials with good adjustable mechanical properties, modifiability, self-healing properties, and entirely degradable properties promote technological progress, but they fail to integrate all the attributes in a single platform. Herein, a design concept is conceived that uses the reversible bond of imine part, the metal ion-ligand coordination, and the crystallites to jointly adjust the internal structure of poly-Schiff base (PSB) metal complexes to achieve cross-linking, high stretchability, self-healing, and complete degradability. The metal ion-imine ligand coordination controls the degree ...

One-Pot Four-Component Synthesis of Acid-Responsive and Degradable Heterochain Polymers with Nonconventional Luminescence

“…The CN bonds of Schiff base derivatives have been widely reported to be unstable under strongly acidic environments. ,, As the obtained polymer structures are rich in CN bonds, they are expected to possess potential acid-mediated hydrolytic postmodification or degradation capabilities. First, the hydrolysis behavior of model compound 5 was investigated to assist in the analysis of the detailed chemical structural changes of polymers upon acidification.…”

“…By the rational design of an MCP strategy, it is possible to obtain such heterochain polymers with degradable or readily modifiable structures and desirable luminescence behaviors. Generally, a polymer could be degraded by the breakage of chemical bonds in its main chains or side chains via chemical reactions between the polymer and specific solvents or chemicals in the environment. , As one of the important types of chemical degradation processes, hydrolytic degradation often occurs in heterochain polymers obtained by condensation polymerization, such as polyesters, polyamides, and Schiff base polymers. − Therefore, the appropriate incorporation of chemical bonds that are liable to undergo hydrolysis in heteroatom-rich polymer structures via novel MCPs could be a feasible strategy for developing functional-degradable heterochain polymers with nonconventional luminescence and stimuli responsiveness.…”

Modification strategy of siloxane antifouling coating: adhesion strength, static antifouling, and self-healing properties

“…The supramolecular structure and reversible metal coordination bonds contribute to improved self-healing properties of the polymer material. Furthermore, the metal coordination bond plays a pivotal role in enhancing the adhesion between the coating and the metal substrate by facilitating chemical interactions between group from the coating and functional groups on the surface of the metal substrate [11,105,106]. Therefore, it is foreseeable that the design of metal coordination bonds in siloxane antifouling coatings holds significant potential value.…”

Cellulose‐Reinforced Programmable and Stretch‐Healable Actuators for Smart Packaging

“…The incorporation of dynamic bonds into polymeric networks of the humidity-responsive actuator is a traditional strategy for improving the self-healing ability of the actuator, including the dynamic covalent bonds, [38,39] hydrogen bonds, [40,41] or coordination bonds. [42,43] Dynamic bonds often lead to the decrease of the mechanical property due to the low bond energy and decrease of the programmability by slowing down the rate of shape recovery. Therefore, it has been a substantial challenge to realize the combination of high mechanical properties, fast self-healing, and shape programmability in an actuator system.…”