Synthesis and swelling behavior of poly(2-dimethylaminoethyl methacrylate-co-N-hydroxymethyl acrylamide) hydrogels

Crosslinked poly(2-(N,N-dimethylamino) ethyl methacrylate-co-N-hydroxymethyl acrylamide) poly(DMAEMA-co-NHMAAM) copolymers were synthesized using ammonium persulfate (APS)/N,N,N',N'-tetramethyl ethylenediamine (TEMED) as initiator/accelerator system in the presence of tetraethyleneglycol diacrylate (TEGDA) as crosslinker in water at 60 degrees C. The effects of comonomer composition in the feed, pH of the swelling medium, and the temperature on the equilibrium swelling (ES) values of hydrogels were investigated. While the initial total monomer concentration was kept constant at 0.5 or 1 mol/l, the contents of APS and TEGDA in the feed were 1 mol% of the total monomers. ES values of DMAEMA-NHMAAM gels increased with the increase in DMAEMA content in the feed. Although DMAEMA-NHMAAM hydrogels containing up to 30 mol% were transparent in appearance, the presence of 40% DMAEMA in the copolymer worsened its transparency. ES values of the copolymer gels with high DMAEMA contents increased with both temperature and the pH of swelling medium. Copyright (c) 2006 John Wiley & Sons, Ltd.