Synthesis and characterization of polyacrylamide and Moringa oleifera seed powder‐based hydrogels

In the present study, crosslinked poly(acrylamide) (PAM)‐based hydrogels were synthesized utilizing different ratios of N,N′ ‐methylenebisacrylamide (0.0026, 0.0078, 0.1297 mol), while incorporating unmodified Moringa oleifera (MO) seed powder at different proportions (2.5%, 5%, and 10% w/w). The primary objective of the study was to rigorously evaluate the steady‐state dynamic swelling, its behaviour at different pH values, surface morphology, and thermal stability, to position the material as a sustainable and low‐cost biosorbent. Through FT‐IR spectroscopy, the formation of the compound hydrogels was confirmed through the interactions between the functional groups of the MO seed powder with the polymer chains. Likewise, the SEM micrographs showed that the incorporation of the natural macromolecule increased the porosity. The best results were obtained in a homogeneous and interconnected structure for the hydrogel with 5% of MO seed powder. In the dynamic swelling tests, the highest water absorption was observed at basic pH, reaching 3050%. Furthermore, the swelling kinetics were best described by the mixed kinetic (MK) model (R 2 > 0.990), confirming the process was governed by a hybrid mechanism of solvent diffusion and structural polymer relaxation; Thermogravimetric analysis revealed that the incorporation of MO improves thermal stability; the hydrogels showed relevant advantages by integrating the MO without chemical modification, using a practical and ecological approach. The results obtained position this type of hydrogel as a sustainable alternative with potential application in water treatment and environmental technology.