Study on plasma‐modified corn stover‐humic acid‐based superabsorbent resin

Abstract

This research aimed to prepare superabsorbent resin from agro-mining waste, which is important for sustainable development and practical application in agriculture and forestry. Corn stover (CS), humic acid (HA), acrylic acid (AA), and acrylamide (AM) were used as raw materials to produce CS-HA-based superabsorbent resin (p-CS-HA-PAA) by plasma modification, and the optimum modification conditions were obtained. The superabsorbent resin was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and contact angle analysis. The adsorption characteristics of the superabsorbent resin were analyzed by kinetic model fitting, and the performances were tested. The results showed that the water absorption capacity could reach 1106.9 g/g under the following optimal process conditions: a discharge time of 180 s, a discharge power of 40 W, and a discharge pressure of 20 Pa. The characterization confirmed that plasma modification could make the surface of the superabsorbent resin rougher, produce more and larger pores, and introduce more hydrophilic groups. The p-CS-HA-PAA conformed to the pseudo-second-order kinetic equation and non-Fickian intradiffusion process in aqueous solution. The chemical resistance, repeated liquid absorption, and water retention properties of the modified resin were better than those of the unmodified resin, which provided a viable way for industrial and agricultural applications.