Deep Investigation of the Effect of DAC Modified by Horner-Wadsworth-Emmons Olefination on the Water Swelling Properties and Strength of Its Hydrogel Composites

In this work, residues from banana cultivation were upgraded by isolating the cellulose fibers, modifying them chemically, and integrating them into superabsorbent polymer (SAP) systems designed for enhanced water uptake. After extraction, the cellulose was oxidized in a controlled manner with sodium periodate to generate dialdehyde cellulose (DAC) with an modular aldehyde content. DAC was further modified through a Horner-Wadsworth-Emmons (HWE) olefination with triethyl phosphonoacetate, yielding cellulose containing sodium propenoate units forming dialdehyde cellulose acrylate (DACAcr). The modified cellulose served as both a grafting agent and a cross-link-enhancing copolymer for the synthesis of hybrid BioSAPs (DACAcr-g-poly(AA-co-IA)) via radical polymerization in water using acrylic acid (AA) and itaconic acid (IA) were copolymerized in aqueous medium in the presence of the modified cellulose, which acted as a graftable macromolecular component. N,N′-methylenebis(acrylamide) (MBA) served as the cross-linking reagent, while potassium persulfate (KPS) initiated the radical polymerization. The incorporation, after oxidation, of a double bond at C2 and C3 positions of the anhydroglucose units, improving their capacity to react with acrylic acid and increasing the number of hydrophilic carboxylate functionalities. This combination produced a flexible and robust polymer network exhibiting enhanced swelling and improved water retention properties which leads to a good compromise between the formation of pores in polymer networks and the mechanical stability of the hydrogel. A thorough analysis of the synthesized SAPs was performed using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and rheological analysis. Kinetic studies revealed that the hybrid BioSAPs exhibited exceptional water absorption capacities, with the SAP-DACAcr0.5eq composite achieving up to 1441 ± 59 g·g–1 in distilled water. The results demonstrate the potential of DACAcr and its derivatives as sustainable, high-performance materials for water retention and management applications, providing an eco-friendly alternative to conventional SAPs. Overall, these results open promising prospects for creating low-cost and environmentally conscious solutions utilizing agricultural waste.