Method for preparing super absorbent resin with cross-linked structure by using potato starch as raw material

The invention discloses a method for preparing super absorbent resin with a cross-linked structure by using potato starch as the raw material, which comprises the following main processes: carrying out neutralization reaction between a sodium hydroxide solution and acrylic acid from which polymerization inhibitor is removed under the cooling of ice-water bath; mixing potato starch with de-ionizedwater and pasting the mixture; mixing the neutralized acrylic acid and the sodium salt solution thereof with the pasted potato starch; adding an evocating agent persulfate and a cross-linking agent N,N'- methylene-bisacrylamide; uniformly stirring the mixture under the protection of nitrogen; heating the mixture by water bath to rise the temperature so as to ensure that the potato starch and the acrylic acid and the sodium salt thereof generate graft copolymerization reaction under the protection of nitrogen; keeping the temperature of the reaction; and baking and crashing to obtain the superabsorbent resin with a cross-linked structure. Compared with similar products, the water absorption of the super absorbent resin is greatly enhanced and the super absorbent resin can absorb a certainamount of heavy metal ion. The super absorbent resin has great effect on the water conservation, the desert control, the environmental improvement and the like of soil in dry regions.