Abstract
A novel superabsorbent composite based on chitosan was prepared by graft copolymerization of acrylic acid (AA) in the presence of kaolin powder using methylenebisacrylamide (MBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator. The synthetic variables (i.e. AA, MBA, and APS concentration, and the kaolin amount) affecting the water absorbency of the resulting superabsorbent composite were studied. Evidence of grafting and kaolin interaction was obtained by comparing the FTIR spectra of the initial substrates with that of the superabsorbent composite. A new absorption band at 1722 cm−1 in the composite spectrum confirmed the kaolin-organic polymer linkage. The effect of kaolin amount showed that increasing this parameter caused the water absorbency of the superabsorbent composite to decrease. The effect of pH on the water absorbency of the superabsorbent was also studied.