Preparation of Salt-Resistance Superabsobent Microspheres by Inverse Suspension Polymerization

Abstract

Novel salt-resistance superabsobent microspheres based on acrylamide (AM), 2-acrylamido-2-methylpropane sulphonic acid (AMPS) by inverse suspension copolymerization using ammonium persulfate (APS) as the initiator and N,N-methylene bisacrylamide (MBA) as the crosslinking agent and surfactant PVA as disperse agent are prepared. The experimental results of salt-resistance superabsobent microspheres show the salt absorbency decreased with the increase of salt concentration; The maximum salt absorbency is 132g/g within 75min in 0.9% NaCl solution and the effect of calcium ion on salt absorbency is much greater than that of sodium ion. FTIR indicates the structure of the acrylamide and 2-acrylamido-2- methylpropane sulphonic acid copolymer. SEM indicates that the number of the micropores largely decreased with the water/oil ratio increasing from 4% to 10%. Elemental analysis indicate that the measured values of carbon, sulfur, nitrogen, hydrogen four elements is very close to theoretical value.