Synthesis and characteristics of interpenetrating polymer network hydrogels composed of alginate and poly(diallydimethylammonium chloride)

Temperature- and pH-responsive interpenetrating polymer network (IPN) hydrogels, with sodium alginate (SA) and poly(diallydimethylammonium chloride) (PDADMAC), constructed by a sequential IPN method, were studied. The characterizations of the IPN hydrogels were investigated by FTIR, DSC, and swelling tests under various conditions. The prepared IPN hydrogels exhibited relatively high swelling ratios, in the range of 380-690%, at 25degreesC. The swelling ratios of SA/PDADMAC IPN hydrogels were pH and temperature dependent. DSC was used for the quantitative determination of the freezing and nonfreezing water contents of the hydrogels. The amount of free water increased with the increasing PDADMAC content of the IPN hydrogels. (C) 2004 Wiley Periodicals, Inc.