Preparation and water absorbent behavior of superabsorbent polyaspartic acid resin

Superabsorbent polyaspartic acid (PASP) resin was prepared from high molecular weight polysuccinimide (PSI), which was synthesized from L-aspartic acid by thermal polycondensation. The effects of the reaction temperature, the reaction time, the concentration of the solvent, the molecular weight of PSI, the concentration of the cross-linking agent, the hydrolysis conditions, and the drying temperature on the swelling ratio of PASP resin were investigated. The swelling ratios of PASP resin in deionized water and saline solution were measured, and the biodegradability of PASP hydrogel was evaluated. The results show that the swelling ratios of PASP resin in deionized water were 100-1,120 g/g depending on the preparation conditions. The swelling ratio of PASP resin in saline solution reached 143 g/g, and PASP resin was a kind of biodegradable material with high water absorbency, so this PASP resin can be used as agricultural and horticultural water-holding material, and in manufacturing of diapers, sanitary napkins, medical products, etc.