Preparation of Psyllium Gum-g-Poly(acrylic acid)/NaMontmorillonite Superabsorbent Composites and Its Adsorption Performance for Cu2+

A series of psyllium gum-g-poly(acrylic acid)/Namontmorillonite(PSY-g-PAA/Na-MMT) superabsorbent composites were prepared by freeradical graft copolymerization among psyllium gum (PSY), acrylic acid (AA) and Namontmorillonite (Na-MMT), using ammonium persulfate (APS) as the initiator and N,N′-methylenebisacrylamide (MBA) as the crosslinker. Effects of Na-MMT mass fraction on the water absorption and the adsorption performance for Cu2+ were investigated, and the swelling behaviors of the superabsorbents in various concentrations of NaCl, MgCl2 and AlCl3 solutions were studied. Infrared spectra confirmed that Na-MMT participated in polymerization reaction. The superabsorbent composite achieved the best water absorption when the mass fraction of Na-MMT was 30%. In addition, the adsorption of superabsorbent composites for Cu2+ from aqueous solution can reach 95% of the saturation adsorption capacity during the initial 15 min, and can achieve adsorption equilibrium within about 60 min.