Technology for synthesis of anti-salt superabsorbent resin under microwave radiation and its performance of absorbability

A new synthesizing process of anti-salt superabsorbent resin was put forward based on the graft copolymerization of acrylic acid (AA) onto starch under microwave radiation by using K₂S₂O₈ as initiator. Salt-resisting superabsorbent resin can be synthesized in 14 min through the optimization of experiment of AA neutralization degree being 40%, m (AA):m (starch)= 4:1 and 0.5 ml 20 g/L K₂S₂O₈ per gram of starch. Under optimal operating conditions, the absorbability for distilled water and 0.9% NaCl solution was 995 g/g and 182 g/g respectively. Effects of process parameters such as resin particle size, AA neutralization degree, ratio of AA and starch, and content of initiator, etc. on the absorbability of superabsorbent were discussed.