Superabsorbent hydrogel composites

Abstract

A new cost‐effective approach to enhance gel strength of superabsorbent hydrogels was invented. Superabsorbent hydrogel composites (SHCs) were prepared through an optimized rapid solution polymerization of concentrated partially neutralized acrylic acid in the presence of a crosslinking agent under normal atmospheric conditions. Kaolin was used as an inorganic component in the polymerization process to strengthen the hydrogel products. FT‐IR spectroscopy was used to confirm grafting of acrylic chains on to the surface of kaolin particles. Morphology of the products was studied by scanning electron microscopy (SEM). Compared with the kaolin‐free hydrogel (control), kaolin caused a reduced equilibrium swelling and swelling rate as low as 17–31% and 19–29%, respectively. Kaolin, however, resulted in enhanced gel strength as high as 21–35% compared to the control. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to study thermal properties of the composites. The SHCs exhibited higher thermal stability than the control. Meanwhile, changes in certain thermal transitions reconfirmed the chemical interaction of the acrylic chain with kaolin. These thermostabilized strengthened superabsorbent hydrogels may be considered as good candidates for agricultural application to retain more water under soil pressure. Copyright © 2003 John Wiley & Sons, Ltd.

Salep‐g‐poly(sodium acrylate)/alumina as an environmental‐sensitive biopolymer superabsorbent composite: Synthesis and investigation of its swelling behavior

“…Similar behaviors have been reported by other researchers. 25 The effect of initiator concentration on the equilibrium swelling capacity of composite was investigated by varying the amounts of APS from 1. ) and then it decreases with further increase in concentration of APS.…”

Synthesis of Montmorillonite/Poly(acrylic acid-co-2-acrylamido-2-methyl-1-propane sulfonic acid) Superabsorbent Composite and the Study of its Adsorption

“…This might be attributed to the graft copolymerization between monomers and -OH groups on the surface of MMT, which brought about copolymers with MMT as crosslinking points and thereby expanded the polymeric network. 22 However, when the content of MMT was over 15%, the excessive crosslinking points would lead to exorbitant crosslinking density and a relatively smaller volume of the network. Consequently, absorbency decreased.…”

Salt- and pH-Resisting Collagen-based Highly Porous Hydrogel

“…So that there have already several studies focusing on improving some hydrogel properties, and further more some modification method seemed effective. [11][12][13][14] On the basis of our former researches, 9,15 we have been interested in preparing a hydrogel which possess relatively high water absorbency under certain load and at atmosphere pressure in salt solution.…”