Ultraviolet photopolymerization and performances of fast‐water absorbing sodium polyacrylate

A kind of fast-water absorbing sodium polyacrylate was prepared by UV polymerization under no crosslinker or initiator condition. Influence of factors, such as exposure time, neutralization degree, polymerization temperature, and monomer concentration on the absorption rate of the resin, were investigated. Its pH sensitivity, average absorption rate in distilled water and saline under load were also studied, respectively. The obtained resin reached to considerably high absorption rate: 4.6 g/g min and 2.6 g/g min even under 8000 Pa load in distilled water and 0.9% NaCl solution, respectively. Simultaneously, the resin displayed excellent water absorbency and water retention capacity. The impact of pH value on absorption rate reflected that the absorption rate was greatly influenced by pH. Synthesized polymer was characterized by FTIR, 1H-NMR, and SEM. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42787.