Synthesized superabsorbent based on cellulose from rice straw for controlled-release of urea

Abstract

Rice straw was used as α-cellulose sources for synthesizing a novel α -cellulose-g-poly(acrylic acid)superabsorbent by graft polymerization between α-cellulose rice straw powder and acrylic acidin aqueous solution. The synthesis and controlled-release of fertilizer from superabsorbent wascarried out.The super absorbent composite was characterized by FTIR, SEM and TGA. The results of FTIR spectra showed OH of α-cellulose rice straw participated in graft polymerization with acrylic acid. The equilibrium water absorbency of super absorbent was investigated by calculating the swelling ratio. The super absorbent composite was swollen in aqueous solution of urea to load urea. Furthermore, the release of urea from loaded super absorbent was analyzed in water. Super absorbent with the highest water absorbency and the slowest profile of release controlled were obtained when the temperature of polymerization reaction was 70 °C.