Preparation and water absorbency of a novel poly(acrylate-co-acrylamide)/vermiculite superabsorbent composite

A novel poly(acrylate-co-acrylamide)/expanded vermiculite (EVMT) superabsorbent composite was synthesized by aqueous solution polymerization method. The water absorbency of the superabsorbent composite still reaches 850 g/g when 50 wt % EVMT is added, which is significant in clecreasing the production cost of the superabsorbent composites. By controlling the molar ratio of acrylic acid monomer and acrylamide monomer, and neutralization degree of acrylic acid, the hydrophilic groups on the composite can be adjusted, and it is found that the collaborative absorbent effect of -CONH2, -COOK, and -COOH groups is superior to that of single -CONH2, -COOK, or -COOH group. (c) 2007 Wiley Periodicals, Inc.