title: Self-healing hydrogels containing reversible oxime crosslinks.
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.
authors.affiliation: George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science & Engineering, Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA. sumerlin@chem.ufl.edu.
authors.forename: Soma
authors.initials: S
authors.lastname: Mukherjee
authors.forename: Megan R
authors.initials: MR
authors.lastname: Hill
authors.forename: Brent S
authors.initials: BS
authors.lastname: Sumerlin
mesh_terms: D020106:Acrylamide / Q000138:chemical synthesis / Q000737:chemistry; D000178:Acrylamides / Q000138:chemical synthesis / Q000737:chemistry; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry*; D010091:Oximes / Q000138:chemical synthesis / Q000737:chemistry*; D044367:Phase Transition; D011092:Polyethylene Glycols; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D000178:Acrylamides; D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D020100:Hydrogels; D010091:Oximes; D011108:Polymers; D014867:Water; D020106:Acrylamide; D011092:Polyethylene Glycols; C099046:N,N-dimethylacrylamide