Preparation and characterization of polyacrylamide cryogels produced from a high-molecular-weight precursor. I. influence of the reaction temperature and concentration of the crosslinking agent

A new type of cryogel was prepared through a reaction of high-molecular-weight polyacrylamide (viscosity-average molecular weight; 3 x 10(6) Da) with glutaraldehyde in a moderately frozen aqueous medium. The influence of the crosslinking agent concentration and temperature of the reaction on the gel fraction yield, swelling characteristics, and morphology of the cryogels was investigated. The dependence of the gel fraction yield on the reaction temperature was bell-shaped. The recognized regularities of the formation of this new type of polyacrylamide cryogel based on a high-molecular-weight precursor were very similar to those observed earlier for polyacrylamide cryogels synthesized through the cryopolymerization of monomeric precursors. (C) 2007 Wiley Periodicals, Inc.