Superabsorbent polymeric materials. XIV. Preparation and water absorbency of nanocomposite superabsorbents containing intercalated hydrotalcite

A series of novel xerogels, based on sodium acrylate (NaA), intercalated hydrotalcite (IHT), and N,N'-methylene-bisacrylamide (NMBA), were prepared by inverse suspension polymerization. The influences of the HT intercalated with acrylic acid (AA-IHT) and with 2-acryloylamido-2-methyl propane sulfonic acid (AMPS-IHT), the content of the IHT in the poly(NaA) gel on the water absorbency, and the initial absorption rate in deionized water and various salt solutions were investigated. Results showed that adding a small amount of IHT could effectively increase water absorbency of the gels, but adding excess IHT could decrease the water absorbency of the gels. In addition, the water absorbency of the gels containing AA-IHT was lower than that containing AMPS-IHT. The initial absorption rate, for the present gels, increased with increasing content of IHT in the copolymeric gels. (C) 2004 Wiley Periodicals, Inc.