Characterization of p(AA-co-AM)/bent/urea and its swelling and slow release behavior in a simulative soil environment
In this work, a novel slow release fertilizer contained 14.98% nitrogen was prepared via free radical polymerization of acrylic acid, acrylamide, and bentonite in the presence of cross-linker (N,N′-methylenebis acrylamide), initiator (potassium persulfate), and nutrient source (urea). The samples were analyzed using a Fourier transform infrared spectrometer, X-ray diffraction, Scanning electron microscopy, Thermogravimetric analysis, and Brunauer, Emmett and Teller analysis. Results showed that the swelling and release behaviors were strongly dependent on the type and concentration of salt solution added to the medium, pH levels of the solutions, and temperature. Moreover, the experimental data indicated that the addition of Bent not only improved water absorbency and water retention capacities but also controlled the release of nutrients. The release kinetic simulation analysis findings showed that the release of urea was predominated by a Case II release mechanism with skeleton erosion. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43082.