Amphoteric superabsorbent polymer based on waste collagen as loading media and safer release systems for herbicide 2, 4‐D

ABSTRACT As release formulations, superabsorbent polymers have attracted considerable attentions to reduce herbicide leaching and mitigate contamination. For this purpose, this study dealt with preparation, characterization, and performance test of a novel amphoteric superabsorbent polymer in adsorption and release of 2, 4‐Dichlorophenoxyacetic acid (2, 4‐D) herbicide. LW‐g‐p(AA‐co‐DMDAAC) was successfully synthesized by using leather waste (LW) as raw material and acrylic acid (AA), and dimethyldiallylammonium chloride (DMDAAC) as monomers. Then, the resulting LW‐g‐p(AA‐co‐DMDAAC) was characterized before and after 2, 4‐D sorption by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). In addition, LW‐g‐p(AA‐co‐DMDAAC) with great equilibrium swelling capacity of 3203 g/g in distilled water, 181 g/g in 0.9 wt % NaCl exhibited excellent performance of swelling. Two absorption peaks appeared at pH = 4 and 7 solely when swelling occurred, and the swelling behavior in pH = 7 satisfied the pseudo first‐order kinetic equation. Moreover, the sorbed 2, 4‐D reached at 68 mg/g and showed sustained release cycle of 45 days under acidic or alkaline conditions. Therefore, the sustained release pattern of 2, 4‐D as well as water absorbency made LW‐g‐p(AA‐co‐DMDAAC) suitable and potential candidate for controlling the release of herbicides to improve utilization and reduce environmental pollution. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48480.