Preparation and hygroscopic property of the Polyacrylamide/MgCl2 hybrid hydrogel

Polyacrylamide/MgCl2 hybrid hydrogel desiccant was prepared from magnesium chloride and polyacrylamide by aqueous solution polymerization. The hybrid hydrogel was synthesized and characterized by X-ray diffraction. The effect of the experimental factors such as content of magnesium chloride, concentration of cross-linking agent, initiator content on hygroscopic performance of the hybrid hydrogel were investigated, furthermore, the hygroscopic swelling kinetic process of the hybrid hydrogel was studied. The results indicate that hybrid hydrogel possessed preferable hygroscopic property under the optimum conditions, the hygroscopic swelling degree achieving 172%. The hygroscopic swelling process of the hybrid hydrogel follows the kinetic pseudo-second-order model, in addition, the swelling rate decreases with the increase of relative humidity