Synthesis Of Superabsorbents Using Acrylic Acid/Sodium Acrylate Grafting On Cassava Starch By Inverse Suspension Polymerization

Starch-based superabsorbents with strong water absorption and retaintion ability,a kind of biodegradable functional polymers,are widely used in various fields such as agriculture,horticulture,physical hygience.In this paper,a starch-based superabsorbent was synthesized by inverse suspension copolymerization using pregelated cassava starch and acrylic acid/sodium acrylate,and it was systematically investigated that applied conditions of the resin,stability of reaction system and experiment amplification.The main contents were as follows:(1)The applied conditions of evalulating the absorbency performance of the resin:screen filter with 100 mesh,resin size within 96?180 ?m,2400:1 of mass ratio of water to resin,pH of 7 for water medium.(2)300?350 rpm of rotative velocity,2:1?3:1 of ratio of oil to water,more than 6mmol·1-1 of concentration of initiator,more than 0.2%,40%and 15%respectively of amounts of crosslinker and assistant agent(PDMS and PEG-4000)account for that of monomer.Within above area,a stable system was formed,and the maximum absorbability of superabsorbent synthesized at appropriate condition as follows:1067 g·g-1 in deionized water and 76 g·g-1 in 0.9%NaCl solution.(3)The graft copolymerization of pregelatinized starch with acrylic acid(AA)was identified by FT-IR;It was analysized that the steric effect of Span-80(lipophilic disperant)is stronger than that of Tween-80(hydrophilic disperant)by SEM,and the thermal stability of resin is better by TG(4)Ten times amplification experiment was accomplished.The reaction system was stability when the rotative velocity was at 150?180 rpm;it was obtained that the proper conditions were 70%of neutralization degree,0.25%and 3.3%respectively of amounts of crosslinker and initiator account for that of monomer,moreover the most significant factor was crosslinker,and the maximum absorbability of superabsorbent in deionized water was 1190 g·g-1;The reaction system was considerable stability by directly reused the waste solvent,which make the the recovery amount of solvent reduce,consequently save cost of production.