Synthesis and Characterization of Montmorillonite-Graft-Acrylic Acid Superabsorbent by Using Glow-Discharge Electrolysis Plasma

Crosslinking graft polymerization of poly acrylic/montmorillonite superabsorbent composite in aqueous solution was prepared by using glow-discharge electrolysis plasma, in which acrylic acid and acid-activated montmorillonite were used as starting materials, N,N-methylenebisacrylamide as a crosslinking agent. To optimize the synthetic conditions, seven important parameters of the graft-polymerization were examined in detail, such as the discharge voltage, discharge time, the neutralization of acrylic acid, post polymerization temperature, amounts of crosslinking agent, montmorillonite and acrylic acid used in this study. The structure, thermal stability and morphology of product were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, respectively. The absorbency of poly acrylic/montmorillonite superabsorbent was examined to yield the following results: 1,834 g/g for distilled water, 116 g/g for 0.05 mol/L and 75 g/g for 0.15 mol/L sodium chloride solution. Such excellent character could be important to use in many fields, for example, in agricultural and horticultural applications.