Extraction of lignin from sugar cane bagasse and its modification into a high performance dispersant for pesticide formulations

Abstract

Com o objetivo de utilizar efetivamente um sub-produto de material não madeireiro, foi extraída lignina do bagaço de cana-de-açúcar via acidificação do licor negro. A lignina extraída do bagaço da cana-de-açúcar (EBL) foi modificada por oxidação, hidroximetilação e sulfonação em um lignossulfonato solúvel em água (EBL-M). O composto foi caracterizado por IR, UV, GPC e análise elementar. Os resultados mostraram que as unidades aromáticas do EBL-M foram mantidas e efetivamente sulfonadas e que a porcentagem de S foi alta (7,82%). A eficiência de dispersão de EBL-M para formulações pesticidas foi comparada com dispersantes comerciais via medição da frequência de suspensão. Como esperado, EBL-M mostrou a mesma eficiência de outros lignossulfonatos comerciais para dispersar kinsperse, quando usados para grânulos de dimetomorfe dispersíveis em água. A caracterização através do peso molecular e do teor de lignossulfonatos no grupo sulfônico, sugeriu que a eficiência dispersante aumentou com o maior teor de grupo sulfônico e maior peso molecular. Quando usado para grânulos de tribenuron dispersíveis em água, a eficiência dispersante de EBL-M foi muito próxima dos dispersantes comerciais.In order to effectively utilize a by-product of non-wood material, lignin was extracted from sugar cane bagasse via acidification of black liquor. The extracted sugar cane bagasse lignin (EBL) was modified by oxidation, hydroxymethylation, and sulfonation into a water-soluble lignosulfonate (EBL-M). It was characterized by IR, UV, GPC and elemental analysis. The results showed that the aromatic units of EBL-M were kept well and it was effectively sulfonated, that the percentage of S was high as 7.82%. The dispersing efficiency of EBL-M for pesticide formulations was compared with commercial dispersants via suspending rate measurement. As expected, EBL-M had the equal optimal dispersing efficiency to kinsperse than other commercial lignosulfonates when being used for dimethomorph water dispersible granules. The characterization of molecular weight and sulfonic group's content of lignosulfonates suggested that the dispersing efficiency increased with higher sulfonic group's content and higher molecular weight. As to being used for tribenuron water dispersible granules, the dispersing efficiency of EBL-M was much close to the commercial dispersants.

Production of carboxymethylated lignin and its application as a dispersant

“…A similar work on the stabilization of ceramic particles using anionic polymeric dispersants, it was reported that the addition of poly acrylic acid and poly ethylene glycol improved the dispersion of ceramic particles in the suspension [54]. In addition, the produced carboxymethylated lignin may also be used as a dispersant in the mining industry (ore suspensions), pesticide formulations, ceramic suspensions and cement admixture [14,17,[55][56] …”

Characterization of Hardwood Soda-AQ Lignins Precipitated from Black Liquor through Selective Acidification

“…However, despite the widespread availability, the chemical utilization of lignin fractions from kraft pulping is practiced only on a limited scale (Gilarranz et al 1998;Lora and Glasser 2002;Calvo-Flores and Dobado 2010;Li and Ge 2011). This is mainly due to their heterogeneous nature, and the lack of capable economic methods in their isolation with high purity (Chakar and Ragauskas 2004;García et al 2009).…”

Utilisation of Lignins in the Bioeconomy: Projections on Ionic Liquids and Molecularly Imprinted Polymers for Selective Separation and Recovery of Base Metals and Gold

“…Structurally, the characterisation of lignin can be well illustrated by the work of Li and Ge [171]. These co-workers utilised the byproduct of a non-wood material for the extraction of lignin.…”

“…According to Li and Ge [171], the relative contents of moisture, ashes and pure lignin content of extracted bagasse lignin, can be measured as follows: an appropriate amount of raw EBL is weighed and placed in an oven and heated to 105 C in air. The corresponding mass loss would Table 4.…”

“…radical scavenger), UV-absorption, antifungal and antibiotic Table 5. Properties of lignin extracted from sugar cane bagasse (EBL) [171].…”