Preparation and properties of novel corn straw cellulose-based superabsorbent with water-retaining and slow-release functions

In this study, novel semiinterpenetrating polymer networks (semi-IPNs) superabsorbent resins with slow-release fertilizer (CSC-g-AA/APP, CSC-g-AA/PVA-APP), based on corn straw cellulose polymer and linear polyvinyl alcohol (PVA), were prepared by solution polymerization. The nitric acid-aqueous solution method was adopted to extract cellulose from corn straw. Ammonium polyphosphate (APP) was introduced to supply nitrogen and phosphorus nutrients. The prepared materials were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). Moreover, the water absorbency and the slow-release performance of CSC-g-AA/APP and CSC-g-AA/PVA-APP were studied. The results indicated that the two superabsorbent resins exhibited excellent water absorbency of 262.8 and 303.2 g/g in distilled water, enhanced the water-holding capacity of soil, and also released nutrients slowly. The cumulative N and P release rates of CSC-g-AA/PVA-APP were 64.47 and 53.53% after 25 days in soil, which were lower than those of CSC-g-AA/APP. The addition of these products into soil significantly reduced the leaching losses of nutrients. Therefore, it can be concluded that the superabsorbent resins with water-retaining and slow-release properties, low production costs, and environment-friendly characteristics, have great potential for applications in agricultural production. (c) 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48951.