Synthesis and the Swelling Behavior of Sodium Alginate Graft Poly (Acrylic Acid-co-acrylamide)/Graphite Oxide Super Absorbent Composite

Sodium alginate graft poly(acrylic acid-co-acrylamide)/graphite oxide (P(AA-co-AM)/GO) super absorbent composite was prepared by solution intercalation copolymerization of acrylic acid (AA), acrylamide (AM) and graphite oxide (GO). The composite was characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, transmission electron microscope and differential scanning calorimetry. The effect of reaction conditions, including the mass ratio of monomers, dosages of cross-linker, initiator and GO as well as the neutralization degree of AA, on the absorption capacities of deionized water and 0.9% NaCl was studied. Water retention properties of the composite were also discussed. It was deduced that the interactions between GO and P(AA-co-AM) copolymer were the intermolecular hydrogen bonds. Thermal stabilities of the composite could be improved by the incorporation of GO. Above all, there was a remarkable improvement of absorption capacities owing to the incorporation of GO. Absorption capacities of water and 0.9% NaCl could be improved from 298.6 and 79.2 g/g, respectively, to 870.5 and 183.3 g/g, respectively, as the dosage of GO increased from 0 to 0.1 g. In addition, there was a remarkable improvement of water retention rates. After drying at 25°C for 8 h the water retention rates could be improved up to 17.9% with the incorporation of GO.