Dynamic Covalent Chemistry of Nucleophilic Substitution Component Exchange of Quaternary Ammonium Salts

Kulchat, Sirinan; Lehn, Jean‐Marie

doi:10.1002/asia.201500604

“…Dynamic exchange in polymeric materials through nucleophilic substitution normally occurs at quaternary ammonium or tertiary sulfonium centers at elevated temperatures. Stoddart and co‐workers utilized the dynamic nature of this reaction in catenanes, and recently the Lehn group extensively studied the exchange kinetics of ammonium salts …”

Section: Nucleophilic Substitutionmentioning

confidence: 99%

Dynamic Covalent Bonds in Polymeric Materials

Chakma

¹

,

Konkolewicz

²

2019

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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.

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“…Dynamic exchange in polymeric materials through nucleophilic substitution normally occurs at quaternary ammonium or tertiary sulfonium centers at elevated temperatures. Stoddart and co‐workers utilized the dynamic nature of this reaction in catenanes, and recently the Lehn group extensively studied the exchange kinetics of ammonium salts …”

Section: Nucleophilic Substitutionmentioning

confidence: 99%

Dynamic Covalent Bonds in Polymeric Materials

Chakma

¹

,

Konkolewicz

²

2019

View full text Add to dashboard Cite

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.

show abstract

“…Dynamic hydrogels are a new generation of hydrogels which are crosslinked by dynamic covalent bonding via S N 2-type nucleophilic substitution [8], imine chemistry [9], Diels-Alder reaction [10], etc. Generally, they are responsive to external stimuli, such as light, temperature, and pH [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Anti-bacterial dynamic hydrogels prepared from O-carboxymethyl chitosan by dual imine bond crosslinking for biomedical applications

Yu

¹

,

Saint-Cyr

²

,

Soussan

³

et al. 2021

International Journal of Biological Macromolecules

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Imine dynamic hydrogels are synthesized via dual-imine bond crosslinking from O-carboxymethyl chitosan (CMCS) and a water soluble dynamer using a 'green' approach. Three dynamers are prepared through reaction of benzene-1,3,5-tricarbaldehyde and di-amino Jeffamine with molar mass of 500, 800 and 1900, respectively. Hydrogels, namely H500, H800 and H1900 are then obtained by mixing CMCS and dynamer aqueous solutions. FT-IR confirms the formation of hydrogels via imine bonding. H1900 presents larger pore size and higher storage modulus as compared to H500 and H800 due to the higher molar mass of Jeffamine linker. The hydrogels exhibit pH sensitive swelling behavior due to electrostatic attraction or repulsion in the pH range from 3 to 10. The highest swelling ratio is obtained at pH 8, reaching 7500% for H800. Self-healing of hydrogels is evidenced by rheological measurements with alternatively applied low and high strains, and by using a macroscopic approach with re-integration of injected filaments. Furthermore, the H1900 membrane exhibits outstanding antibacterial activity against an E. coli suspension at 10 8 CFU mL −1 . Therefore, dynamic hydrogels synthesized from CMCS and Jeffamine present outstanding rheological, swelling, self-healing and antibacterial properties, and are most promising as healthcare material in wound dressing, drug delivery and tissue engineering.

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Dynamic Covalent Chemistry of Nucleophilic Substitution Component Exchange of Quaternary Ammonium Salts

Cited by 28 publications

References 103 publications

Dynamic Covalent Bonds in Polymeric Materials

Dynamic Covalent Bonds in Polymeric Materials

Dynamic Covalent Bonds in Polymeric Materials

Anti-bacterial dynamic hydrogels prepared from O-carboxymethyl chitosan by dual imine bond crosslinking for biomedical applications

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