DESIGN OF POROUS MATERIALS FROM OXIDIZED SUGARCANE BAGASSE MICROFIBRIL

The global demand for sustainable products has increased, emphasizing materials and technologies that reduce environmental impact. Biomass presents a promising alternative due to its renewable nature and carbon neutrality. Cellulose, the most abundant biopolymer in lignocellulosic biomass, can be processed in its fibrillar form or through the regeneration of solubilized cellulose into various morphologies. In this study, cellulose microfibers (MFC) with residual lignin were directly isolated from sugarcane bagasse using a simplified oxidation process developed by our research team. Radical oxidation mediated by the catalyst 2,2,6,6- tetramethylpiperidine-1-oxyl (TEMPO) utilized 10 and 20 mmol/g of the oxidizing agent sodium hypochlorite.The MFC isolated with a lower degree of oxidation (MFC10) is yellowish due to a higher lignin concentration and contains larger particles. As the degree of oxidation increases (MFC20), the color becomes lighter, and the particle size decreases. Dispersions containing 3 and 6 % w/w of MFC10 and MFC20, with and without mechanical treatment, were utilized to create poros materials, which possess potential applications in packaging and environmental decontamination. When dried, all samples have high porosity (above 90%), low density (ranging from 30 to 70 mg.cm^-3) and physical integrity. However, they disintegrate easily in water, limiting their application. Therefore, these porous materials were chemically cross-linked with citric acid (CA) and 1,2,3,4-butanetetracarboxylic acid (BTCA), in the presence of sodium hypophosphite (SHP). Preliminary results show that the mechanical properties and water stability of MFC20 improved significantly with the crosslink. However, samples with high lignin (MFC 10) content disintegrated in water, indicating that residual lignin negatively impacts the reaction with CA and BTCA.