Preparation of starch-graft-poly(acrylamide)/attapulgite superabsorbent composite

A novel starch-graft-poly(acrylamide)/atta- pulgite superabsorbent composite was synthesized by graft copolymerization reaction of starch, acrylamide (AM), and at- tapulgite micropowder using N.N-methylene-bisacrylamide (MBA) as a crosslinker and ammonium persulphate (APS) as an initiator in aqueous solution, followed by hydrolysis with sodium hydroxide. The effects on water absorbency, such as amount of crosslinker, initiator, attapulgite, weight ratio of acrylamide to starch in the feed, gelatinization conditions of starch and molar ratio of NaOH to acrylamide, and so forth, were investigated. These superabsorbent composites were characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The water ab- sorbencies for these superabsorbent composites in water and saline solution were investigated, and water retention tests were carried out. Results obtained from this study showed that the water absorbency of superabsorbent composite synthe- sized under optimal synthesis conditions with an attapulgite content of 10% exhibit absorption of 1317 g H2O/g sample and 68 gH 2O/g sample in distilled water and in 0.9 wt % NaCl solution, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1351-1357, 2005