Allann Karlos Alves da Mata, Vinícius Taveira de Andrade Felipe, Selma Elaine Mazzetto, Diego Lomonaco, Francisco Avelino
International journal of biological macromolecules 2022 Jun 30The optimization of the parameters involved in lignin extraction is crucial for obtaining a lignin with specific structural features for its further valorization. The aim of this work was to develop an eco-friendly organosolv protocol for tuning the acetylation degree of coconut shell lignins (CSLs) by using MgCl2 and HCl as catalyst and co-catalyst, respectively. CSLs were obtained by mixing coconut shell powder with 90% v/v acetic acid combined to no catalyst, 2% v/v HCl and 2% w/v MgCl2 (1, 2 and 3 h) and 2% w/v MgCl2 combined to 0.1, 0.25 and 0.5% v/v HCl (2 h) at 110 °C. CSLs were characterized by FTIR, 1H NMR, GPC and TGA. The effects of the acetylation degree were evaluated on their antioxidant activity (DPPH assay) and UV-blocking capacity in sunscreen formulations. The results have shown that the use of HCl as co-catalyst increased the lignin yield (from 21.4 to 48.8%) and the acetylation degree (from 0.81 to 1.58 mmol g-1), which positively affected thermal (200 < Tonset < 226 °C), antioxidant (46.6 < IC50 < 67.5 μg mL-1) and UV-blocking capacities of CSLs. It can be concluded that the design of the organosolv process was capable of generating lignins with peculiar functionalities and properties through an eco-friendly protocol. Copyright © 2022 Elsevier B.V. All rights reserved.
Allann Karlos Alves da Mata, Vinícius Taveira de Andrade Felipe, Selma Elaine Mazzetto, Diego Lomonaco, Francisco Avelino. Development of an eco-friendly acetosolv protocol for tuning the acetylation of coconut shell lignin: Structural, antioxidant, solubility and UV-blocking properties. International journal of biological macromolecules. 2022 Jun 30;211:271-280
PMID: 35577184
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