الفهرس 
Synthesis and characterization of superabsorbents based on modified starch for improving water and saline absorbency
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Abstract
New starch derivatives containing sulfonated functional groups were prepared through intermediate triazinyl compounds. Four different bridging compounds were synthesized and characterized via spectral analysis. The sulfonated triazinyl compounds were reacted with native starch to obtain different density of sulfonic acid groups on starch backbone. The sulfonic acid groups were introduced in different degree of substitutions (0.043, 0.032, 0.006 and 0.008). A new amphoteric superabsorbent based on sodium starch sulfonate (SSS) is prepared by an indirect method. The sodium starch sulfonate was then graft-polymerized with acrylonitrile and the nitrile groups of the sodium starch sulfonate -g-polyacrylonitrile were converted to a mixture of hydrophilic carboxamide and carboxylate groups by alkaline hydrolysis. Optimum conditions of the co-polymerization were studied and recorded for 120 min polymerization time, 0.75% Ammonium persulfate (APS) associated with sodium bisulfite (50% of APS), 65oC for polymerization temperature and double molar ratio of acrylonitrile to the starch derivatives. The grafted acrylonitrile and the saponified products were spectrally characterized. The hydrogel based on the sulfonated starch derivatives showed superior water absorbency for both distilled and saline solutions over that of native starch