Synthesis and swelling properties of corn stalk-composite superabsorbent

A corn stalk-composite superabsorbent with water absorbency of 660 g/g within 30 min, was prepared by graft copolymerization with acrylic acid (AA), acrylamide (AM), sodium 4-styrenesulfonate (SSS), and corn stalk in aqueous solution after the pretreatment of corn stalks (CS), using N,N-methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) and sodium bisulfite (SBS) as redox initiators. Factors influencing water absorbency and gel strength of the superabsorbent composite, such as the amount of corn stalk, the mass ratio of acrylic acid to acrylamide, the degree of neutralization for AA and the amount of crosslinker, were investigated. Morphologies and structure of the corn stalk-composite superabsorbents were characterized by FTIR, SEM and optical microscope. FTIR spectra indicate the structure of corn stalk graft-copolymer. SEM data show that the discontinuous sheet structures of corn stalks disappear and gel aggregates with many large microporous holes and small capillary pores are formed after corn stalk graft modification. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013