Self-healing hydrogels containing reversible oxime crosslinks

Soft Matter. 2015 Aug 14;11(30):6152-61. doi: 10.1039/c5sm00865d. Epub 2015 Jul 6.

Abstract

Self-healing oxime-functional hydrogels have been developed that undergo a reversible gel-to-sol transition via oxime exchange under acidic conditions. Keto-functional copolymers were prepared by conventional radical polymerization of N,N-dimethylacrylamide (DMA) and diacetone acrylamide (DAA). The resulting water soluble copolymers (P(DMA-stat-DAA)) were chemically crosslinked with difunctional alkoxyamines to obtain hydrogels via oxime formation. Gel-to-sol transitions were induced by the addition of excess monofunctional alkoxyamines to promote competitive oxime exchange under acidic conditions at 25 °C. The hydrogel could autonomously heal after it was damaged due to the dynamic nature of the oxime crosslinks. In addition to their chemo-responsive behavior, the P(DMA-stat-DAA) copolymers exhibit cloud points which vary with the DAA content in the copolymers. This thermo-responsive behavior of the P(DMA-stat-DAA) was utilized to form physical hydrogels above their cloud point. Therefore, these materials can either form dynamic-covalent or physically-crosslinked gels, both of which demonstrate reversible gelation behavior.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acrylamide / chemical synthesis
  • Acrylamide / chemistry
  • Acrylamides / chemical synthesis
  • Acrylamides / chemistry
  • Biocompatible Materials / chemical synthesis
  • Biocompatible Materials / chemistry*
  • Cross-Linking Reagents / chemistry*
  • Hydrogels / chemical synthesis
  • Hydrogels / chemistry*
  • Oximes / chemical synthesis
  • Oximes / chemistry*
  • Phase Transition
  • Polyethylene Glycols
  • Polymers / chemical synthesis
  • Polymers / chemistry
  • Temperature
  • Water / chemistry

Substances

  • Acrylamides
  • Biocompatible Materials
  • Cross-Linking Reagents
  • Hydrogels
  • Oximes
  • Polymers
  • Water
  • Acrylamide
  • Polyethylene Glycols
  • N,N-dimethylacrylamide