Preparation and swelling behaviors of porous hemicellulose‐g‐polyacrylamide hydrogels

Novel porous hydrogels were successfully synthesized from hemicelluloses (HCs) and acrylamide (Am) with poly(ethylene glycol) (PEG) as the porogen. The prepared hydrogels were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy (SEM). The results show that the used PEG was not involved in the formation process of the hydrogels, and the HC‐g‐polyacrylamide hydrogels displayed a higher thermal stability than the hemicellulosic polymer. SEM analysis confirmed that the prepared hydrogels had porous structures. The effects of the Am/HC ratio, the amount and molecular weight of PEG and the amount of the crosslinker N,N‐methylene bisacrylamide on the swelling ratio of the prepared hydrogels were investigated in detail. The experimental data were fitted with the exponential heuristic equation and the Schott second‐order dynamic equation. The diffusion of water molecules into the hydrogel network was found to be non‐Fickian in behavior, and the swelling kinetics could be described by the Schott second‐order dynamic equation. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013