Inverse suspension polymerization of sodium acrylate

A superwater-absorbent sodium polyacrylate was synthesized by inverse suspension polymerization, using Span60 as the dispersant, cyclohexane as the organic phase, N,N′-methylene bisacrylamide as the crosslinking agent, and potassium persulfate as the initiator. The effect of reaction conditions such as reaction time, crosslinking agent, and dispersant on deionized-water and saline solution absorbability, average particle size, and distribution of the sol–gel of the resin is discussed. The deionized-water and saline solution absorbabilities of sodium polyacrylate prepared at proper conditions were 300–1200 and 50–120, respectively; the number-average particle size was 10–50 μm and the gel portion was 20–85% by weight.