Reentrant Phase Transition and Fast Responsive Behaviors of Poly{N-[3-(dimethylaminopropyl)] Methacrylamide} Hydrogels Prepared in Poly(ethylene glycol) Solutions


Demirel G. B. , ÇAYKARA T.

JOURNAL OF APPLIED POLYMER SCIENCE, vol.113, no.1, pp.547-552, 2009 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 113 Issue: 1
  • Publication Date: 2009
  • Doi Number: 10.1002/app.30120
  • Title of Journal : JOURNAL OF APPLIED POLYMER SCIENCE
  • Page Numbers: pp.547-552

Abstract

Macroporous temperature-sensitive poly{N-[3-(dimethylaminopropyl)] methacrylamide} hydrogels were synthesized by free-radical crosslinking polymerization of the monomer N-[3-(dimethylaminopropyl)] methacrylamide and the crosslinker N,N'-methylenebisacrylamide in aqueous solutions at 22 degrees C. Poly(ethylene glycol) (PEG) with a molecular weight of 1000 g/mol was used as the pore-forming agent during the polymerization reaction. The concentration of PEG in the polymerization solutions were varied between 0 and 18 wt %, whereas the crosslinker (N,N'-methylenebisacrylamide) concentration was fixed at 2 wt % (with respect to the monomer). The effects of the PEG concentration on the thermo-induced phase-transition behavior and the chemical structure, interior morphology, and swelling/deswelling kinetics were investigated. Normal-type hydrogels were also prepared under the same conditions without PEG. An interesting feature of the swelling behavior of both the normal-type and macroporous hydrogels was the reentrant phase transition, in which the hydrogels collapsed once and reswelled as the temperature was continuously increased. Scanning electron micrographs revealed that the interior network structure of the hydrogels prepared in PEG concentration in the polymerization solution. This more porous matrix provided numerous water channels for water diffusion in or out of the matrix and, therefore, and improved responsive rate to external temperature change during the deswelling and swelling processes. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 547-552, 2009