Preparation of low cost superabsorbent hydrogel by urea and acrylic acid

Abstract

We describe a method for the synthesis of low cost superabsorbent hydrogel (LCSH) via solution polymerization with urea, acrylic acid (AA) and N,N'-methylenebisacrylamide (MBA). The various factors influencing the water absorbency of LCSH material were studied, including the mole ratio of urea to AA, weight ratio of MBA to AA (wt%) and neutralization degree of AA. The optimal conditions were found as follows: n(urea):m(AA)=1.6:1, the weight ratio of MBA to AA (wt%) and the neutralization degree of AA was 0.005% and 85%, respectively. The maximum absorbency in distilled water was 835g/g. The characteristics of LCSH material were investigated by Fourier Transform Infra Red (FTIR), scanning electron microscope (SEM) and precision electronic balance (FEB). The results indicated that LCSH material was successfully developed and it’s broad network structure offers the hydrogels excellent water absorbency.