Synthesis of superabsorbent resin of konjac glucomannan grafting acrylic acid/acrylamide

A superabsorbent resin was prepared through free-radical polymerization in aqueous solution,which used konjac glucomannan(KGM),acrylic acid(AA)and acrylamide(AM)as raw materials.Graft polymerization was initiated by potassium persulfate(K2S2O8),with N,N′-methylene-bis-acrylamide(NMBA)was used as crosslinking agent .The relationships between the water absorption of the resin and the amounts of initiator,crosslinker,AA and AM as well as reaction temperature,reaction time were studied.This superabsorbent polymer was capable of absorbing distilled water up to 720 times and 0.9%NaCl solution 110 times in its saturated state at ambient temperature when the mass ratio of KGM to monomer was 1∶4,the amount of initiator was 0.35%(based on the weight of monomer),the neutralization degree of monomer was 80 %,the reaction temperature was 55～65℃,and the amount of crosslinker was 0.075%(based on the weight of monomer).Experimental results indicated that the introduction of nonionic group would be suitable for improving absorption ability and salt-resistance of the resulting hydrogels.