Preparation of superabsorbent composite(s) based on dialdehyde cellulose extracted from banana fiber waste.

The study focus is the valorization of banana agriculture by products by the extraction and derivatization of cellulose and its incorporation in formulations to produce superabsorbent materials endowed with high water absorption performances. The extracted cellulose (BP) was subjected to a controlled oxidation by sodium periodate to convert it to cellulose dialdehyde (DAC) with controlled aldehyde content. The cellulosic materials were incorporated into a suspension containing acrylic acid (AA) and itaconic acid (IA) to produce composite hybrid hydrogels (SA-BP/SA-DAC) by radical chain polymerization in water, using N,N-methylene-bis-acrylamide (MBA) as a cross-linking agent and potassium persulfate (KPS) as an initiator. The prepared materials were characterized using techniques such as Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and rheological analysis. Additionally, the absorption and re-swelling capacities of the superabsorbent composites (SAPs) were assessed through kinetic studies in water and NaCl solution. Notably, dialdehyde cellulose (DAC), due to its low crystallinity index, hydrophilicity (attributed to aldehyde and hemiacetal functions), and high polarity, holds promise for enhancing the swelling and water retention capacity of the hydrogel. A water absorption capacity as high as 1240±60 g.g-1 was obtained for SA-DAC with a DAC content of 5 %wt. Additionally, the reusability of the SAPs was evidenced.