Synthesis of super absorbent resin of starch-AA-AM-MA by inverse suspension polymerization

A super-absorbent resin was synthesized by inverse suspension copolymerization,using industrial grade acrylic acid(AA),methyl acrylate(MA) that contain inhibitor and cassava starch,acrylamid(AM),with self-made agent as dispersing agent,cyclohexane as continuous phase,potassium persulfate and sodium bisulfite as initiator,N,N-mythylene bisacrylamide as cross-linking agent.The result shows that the optimum reaction conditions:m(starch) ∶m(AA) ∶m(AM)=1.0 ∶4.5 ∶0.9,dosage of MA and cross-linking agent 5.0%,0.3%(based on the total mass of AA and AM),concentration of initiator(twice initiation) 2.0,13.5 mmol/L,the ratio solvent to water phase 1.90 ∶1.00(v/v).Based on above conditions,the prepared resin can absorb deionizing water over 600 times of its own weight and NaCl aqueous solution(9 g/L)over 60 times.recovery of cyclohexane 97.3%.The absorbing capacities of resin for water and salt-water is improved 20% and the shape of product from adhesive particles change to dispersed particles when the content of MA is proper.