ABSTRACT Conventional petroleum‐based superabsorbent hydrogels suffer from high cost, poor degradability, and environmental concerns. To address these issues, a biodegradable bio‐based superabsorbent hydrogel (SL‐P(AA‐AMPS)/CA) was successfully synthesized via open‐system aqueous solution polymerization, with sodium lignosulfonate (SL) serving as the bio‐based framework, acrylic acid (AA) and 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS) as monomers, and citric acid (CA) as a crosslinking modifier. The hydrogel's structure was systematically characterized by Fourier transform infrared spectroscopy (FT‐IR), x‐ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). These analyses conclusively confirmed the successful grafting of SL onto the polymer chains and the establishment of a three‐dimensional network structure. The hydrogel exhibited exceptional water absorption capacities of 899.8 g/g in deionized water and 110.6 g/g in 0.9% NaCl solution, with a dense, uniformly porous microstructure featuring smooth pore walls and structural stability. The incorporation of SL and CA not only enhanced hydrophilicity and absorption performance but also significantly improved biodegradability through the introduction of microorganism‐degradable functional groups (‐C‐O, ‐C = O‐NH, ‐COOH, ‐OH), achieving a 25.7% soil degradation rate within 28 days. This work presents an innovative approach utilizing biomass molecules to mitigate environmental pollution from conventional superabsorbent hydrogels, advancing the development of sustainable, high‐performance hydrogel materials toward green applications.
Shu et al. (Sun,) studied this question.