Starch Graft Modified The Preparation Of Superabsorbent,

The soluble starch was modified by means of graft copolymerization in experiment, in order to prepare starch-based superabsorbent polymers with high absorbency, excellent hydrogel strength and good dispersancy.Two kinds of starch-based superabsorbent polymers were synthesized through solution polymerization via a redox initiator system of ammonium persulfate and sodium bisulfite, N,N-methylenebisacrylamide as cross-linking. They were starch-g-AA superabsorbent polymers and starch-g-AA-AM superabsorbent polymers.Effects of process parameters both on the graft copolymerization and the absorbency of superabsorbent resin were discussed.Starch-g-AA superabsorbent polymers was synthesized under the optimal conditions.The reaction temperature was 55℃, the reaction time was 3h, AA:ST was 3:1, the concentration of initiator was 0.40%, the neutralization degree of AA was 70%.The absorbency of distilled water was 865g/g.Starch-g-AA-AM superabsorbent polymers was synthesized under the optimal conditions.The reaction temperature was 45℃, the reaction time was 3h, Monomer:ST was 3.25:1, AA:AM was 1.5:1, the concentration of initiator was 0.35%.The absorbency of distilled water was 700g/g.The methods we used were simple and the products we prepared had excellent characteristic at the same time.The structure of copolymers were fully analysed by IR, SEM and X-ray diffraction.