Alginate-based superabsorbent hydrogels composed of carboxylic acid-amine interaction: Preparation and characterization

Abstract

Preparation of superabsorbent hydrogels based on sodium alginate was investigated by mixing aqueous sodium alginate solution and aqueous multivalent amine (ethylenediamine, L-lysine, chitosan) solution, followed by HCl addition. After precipitation in methanol, vacuum drying, and pulverization with mixer, granule products with acid-base interaction were obtained. The preparation condition was investigated by changing the feed amount of amine compound. Among those examined, the highest water absorbency was obtained with the sample for chitosan feed ratio to sodium alginate of 100 mol%, reaching 410 g/g in pure water, 100 g/g in 0.9 % solution, and 80 g/g in 3.5 % NaCl solution. Hydrogels in the present study exhibited good biodegradability irrespective of amine compound.