Swelling and Characterization Behavior of Anti-salt Superabsorbent based on Carboxymethyl Cellulose-g-PAA-co-BuMC Hydrogel

A novel superabsorbent hydrogel was synthesized via crosslinking graft copolymerization of acrylacid (AA) abd buthylmethacrylate (BuMC) onto Carboxymethyl cellulose (CMC) backbones in a homogeneous solution. The methylenebisacrylamide (MBA) and Ceric amounium sulfate (CAN) were used as water-soluble crosslinker and initiator, respectively. Evidence of grafting was obtained by comparing FTIR, SEM spectra of CMC and the graft copolymer as well as solubility characteristics of the products. A mechanism for the superabsorbent hydrogel formation was also suggested. The affecting parameters onto swelling capacity of the synthesized hydrogel, i.e., concentration of AA/BuMC waight ratio, MBA as well as reaction temperature were systematically optimized for obtaining maximum absorbency as possible as. The swelling capacity of hydrogels was also measured in various salt solutions (LiCl, NaCl, KCl, MgCl2, CaCl2, SrCl2, BaCl2, and AlCl3). Due to high swelling ability in salt solutions, the hydrogel may be referred as "anti-salt superabsorbent" polymers. The overall activation energy for the graft copolymerization reaction was found to be 374 kJ/mol. The swelling kinetics of the hydrogels in distilled water was preliminary investigated.