Tailored Bio‐Based Sodium Alginate/Polyacrylamide Hydrogels With Enhanced Adhesive and Load Bearing Ability

ABSTRACT This study focuses on the synthesis of a bio‐based, viscoelastic hydrogel derived from sodium alginate with enhanced adhesive properties suitable for diverse applications. The hydrogel network was formed through free radical polymerization, employing N, N′‐methylene bisacrylamide (MBA) as a crosslinking agent to establish a chemically crosslinked matrix. Comprehensive characterization using Fourier‐transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and simultaneous thermal analysis (STA) confirmed the successful synthesis, morphological features, and thermal stability of the hydrogels. The adhesive performance was systematically evaluated through rheological testing, measuring both adhesive strength and viscoelastic parameters such as storage ( G ′) and loss ( G ″) moduli under varying frequencies and strain conditions. The findings demonstrate that intermolecular interactions within the polymeric network critically influence adhesive efficacy. By modulating sodium alginate concentrations (0.1, 0.2, and 0.3 g), optimal adhesive properties were attained at 0.2 g. Adhesion tests conducted on multiple solid substrates including glass, steel, wood, and textiles revealed superior adherence particularly on metal, wood, and glass surfaces. These results underscore the potential utility of the synthesized hydrogel as a versatile adhesive material for biomedical and industrial applications.