Salt-resistant superabsorbents from inverse-suspension polymerization of PEG methacrylate, acryamide and partially neutralized acrylic acid

The Superabsorbent resin was synthesized based on poly(ethylene glycol) methacrylate (PEGMA), acrylic acid(AA) and acrylamide(AM) by inverse suspension polymerization. By plenty of trial and error in previous works, we used mono-octadecyl phosphate as the dispersant to stabilize the suspension system effectively. In addition, the monomer we employed, PEGMA, also took a role as dispersant, this resulted in the shortage of mono-octadecyl phosphate to reduce the consumption of raw materials effectively. The effects of temperature, the concentration of monomers, the dosage of initiator, crosslinking agent and marcomonomer on the absorbency were studied. At the same time, the kinetics of swelling also was studied. The maximum absorption of the resin reached 930 mL/g and 94 mL/g for deionized water and 0.9 wt % NaCl solution, respectively.