Research On The Preparation And Capability Of Waxy Wheat Starch Super Absorbent Resin

In order to get waxy starch superabsorbent resin, waxy wheat starch was selected as the material of this research, the preparatory processing, structure and capability of waxy wheat starch superabsorbent resin were studied, the influence on water-absorbency in different drying conditions of waxy wheat starch superabsorbent resin were compared based on the systematic analysis of waxy wheat starch grain structure, starch composing, Dextrinize characteristic and paste characteristics. The results were as follows:The waxy wheat starch grain had obvious polarization cross and the starch grain diameter of A type was bigger than B. The amylose content of waxy wheat A and B type starch are extremely low, 2.81% and 0.30% respectively. The waxy wheat starch paste was hot instability and not easy to form gel, the aging speed was slow. The paste diaphaneity was not high, but the freeze-melting stability was better. The swelling characteristics were changed because of the amylose content lower.The optimum preparatory processing conditions of waxy wheat starch superabsorbent resin obtained were neutralization degree of acrylic acid/pH5.4, the waxy wheat starch consistency 9%, reaction temperature 55℃, initiator 4% ammonium persulfate solution 6.5 mL, cross-linking agent 2% N, N'-methylene-bisacrylamide solution 0.75 mL. The distilled water absorbency of prepared superabsorbent resin reached about 1169.6 g·g-1 under these conditions. The superabsorbent resin was graft copolymer by the waxy wheat starch and acrylic acid; the distilled water absorbency and salt water absorbency of the waxy wheat starch superabsorbent resin reached 1169.6 g·g-1 and 88.6 g·g-1 respectively, but the resistance capability on salt was not better. In the condition of 30℃, 40℃, and 60℃respectively, the water retaining capacity of the waxy wheat starch superabsorbent resin was better than Kehan 98 commodity SAR. The heat stability, reserve stability and repeat use capability of the waxy wheat starch superabsorbent resin were better, however the resistance acidity or alkalescence capability was faintish. The soil water retaining rate and changes of coacervate quantity could be improved effectively by waxy wheat starch superabsorbent resin, the improving soil effect adding 1% waxy wheat starch superabsorbent resin was better than adding 1% Kehan 98 commodity SAR. The optimum preparatory processing conditions of waxy wheat starch superabsorbent resin with salt-resistance obtained were neutralization degree of acrylic acid/pH5.8, acrylic amide14 g, methyl acrylate 1 mL, reaction temperature75℃, initiator 4% ammonium persulfate solution 5 mL, cross-linking agent 2% N, N'-methylene-bisacrylamide solution 0.5 mL. The salt water absorbency of prepared superabsorbent resin reached 62.1 g·g-1 under these conditions. The water absorbency of waxy wheat starch superabsorbent resin treating in 80℃drying oven was obvious lower than in -60℃vacuum freeze-drying, the waxy wheat starch superabsorbent resin had stronger water absorbency and salt-resistance treating in vacuum freeze-drying.