| production method | formula: starch: water = 1:10 (mass ratio) in a four-mouth bottle, add a certain amount of purified starch and deionized water (mass ratio is about 1:10), under constant stirring, keep a constant temperature at 80 ℃ for 1h, then cool to 40 ℃, and introduce nitrogen into the reaction system for 15min, start dropping a certain amount of 0.1mol/m3 H2SO4 and 0.1mol/m3 KMnO4 mixed solution, after dropping the solution for 0.5h, add a certain amount of acrylamide aqueous solution in several times, stir at constant temperature for 2-3h, and stop passing nitrogen. Adjust the pH value to 7 with 4mol/m3 NaOH solution, soak with ethanol precipitation, filter and dry dry, then dry to constant weight at 50 ℃, and grind to obtain graft copolymer. Weigh a certain amount of graft copolymer into a three-mouth bottle, add a certain amount of 4mol/m3 NaOH solution to the three-mouth bottle, continuously stir at 90-100 ℃, saponify at constant temperature for 2-4h, cool the saponified substance to room temperature, adjust pH = 7 with acetic acid, precipitate and soak with anhydrous ethanol, remove salt and other electrolytes from the saponified substance, filter and dry, and vacuum dry at 50 ℃, that is, super absorbent resin. |