Synthesis and network parameters of hydrophobic poly(N-[3- (dimethylaminopropyl)]methacrylamide-co-lauryl acrylate) hydrogels

Caykara T., Birlik G.

Journal of Applied Polymer Science, vol.101, no.6, pp.4159-4166, 2006 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 101 Issue: 6
  • Publication Date: 2006
  • Doi Number: 10.1002/app.23759
  • Journal Name: Journal of Applied Polymer Science
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.4159-4166
  • Keywords: poly(N-[3-(dimethylaminopropyl)]methacryl-amide-co-lauryl, acrylate), hydrophobic hydrogels, crosslinking networks, SWELLING BEHAVIOR, PHASE-TRANSITION, RELEASE, WATER, GELS
  • Ankara Haci Bayram Veli University Affiliated: No

Abstract

Hydrophobic poly(N-[3-(dimethylaminopropyl)]methacrylamide-co-lauryl acrylate) [P(DMAPMA-co - LA)] hydrogels with different LA content were synthesized by free-radical crosslinking copolymerization of corresponding monomers in water by using N,N-methylenebis(acrylamide) as the crosslinker, ammonium persulfate as the initiator, and N,N,N′,N′- tetramethylethylenediamine as the activator. The swelling equilibrium of the hydrogels was investigated as a function of temperature and hydrophobic comonomer content in pure water. An interesting feature of the swelling behavior of the P(DMAPMA-co-LA) hydrogels with low LA content was the reshrinking phase transition where the hydrogels swell once and collapse as temperature was varied in the range of 30-40°C. The average molecular mass between crosslinks (M̄c) and polymer-solvent interac tion parameter (Χ) of the hydrogels were calculated from equilibrium swelling values. The enthalpy (ΔH) and entropy (ΔS) changes appearing in the Χ parameter for the hydrogels were determined by using the Flory-Rehner theory based on the phantom network model of swelling equilibrium. The positive values for ΔH and ΔS indicated that the hydrogels had a positive temperature-sensitive property in water, that is, swelling at a higher temperature and shrinking at a lower temperature. © 2006 Wiley Periodicals, Inc.