Data/hora: 16/06/2024 04:13:40

Biblioteca(s): 	Embrapa Florestas.	
Data corrente: 	17/05/2024	
Data da última atualização: 	17/05/2024	
Autoria: 	CLARO, F. C.; LIMA, G. G. de; LIMA, T. A. M. de; HANSEL, F. A.; MATOS, M.; AVELINO, F.; OLIVEIRA, D. R.; LOMONACO, D.; MAGALHAES, W. L. E.	
Afiliação: 	FRANCINE C. CLARO, UNIVERSIDADE FEDERAL DO PARANÁ; GABRIEL G. DE LIMA, UNIVERSIDADE FEDERAL DO PARANÁ; TIELIDY A. M. DE LIMA, TECHNOLOGICAL UNIVERSITY OF THE SHANNON; FABRICIO AUGUSTO HANSEL, CNPF; MAILSON MATOS, SENAI; FRANCISCO AVELINO, INSTITUTO FEDERAL DE EDUCAÇÃO, CIÊNCIA E TECNOLOGIA DO CEARÁ; DAVI R. OLIVEIRA, UNIVERSIDADE FEDERAL DO CEARÁ; DIEGO LOMONACO, UNIVERSIDADE FEDERAL DO CEARÁ; WASHINGTON LUIZ ESTEVES MAGALHAES, CNPF.	
Título: 	Characterisation of laccase-mediated lignin polymerisation: implications for molecular weight, thermal stability, and electrical properties.	
Ano de publicação: 	2023	
Fonte/Imprenta: 	Biomass Conversion and Biorefinery, 2023.	
DOI: 	http://dx.doi.org/10.1007/s13399-023-05040-9	
Idioma: 	Português	
Notas: 	First online.	
Conteúdo: 	Kraft lignin was oligomerised using a bulk laccase solution in varying amounts of buffer and ethanol solvents. The activity of laccase and kinetic parameters was analysed by adjusting the buffer pH and ethanol:buffer ratio. The qualitative weighted average molecular weight (Mw) distribution showed significant variation when ethanol (40:60) solvent was used. GPC analysis confirmed the presence of fractions with higher molecular weight, where the Mw after 30 min was 7859, compared to 90 min in the buffer medium, where M w was only 1779. These condensed units exhibited lower antioxidant values, characteristic of a polymerisation reaction. Py-GC/MS analysis demonstrated that the sample with the highest molecular weight displayed increased G-type lignin units and higher levels of polysaccharides residue compared to the original kraft lignin. The addi- tion of ethanol as a green solvent, mixed with buffer, resulted in a 4.4-fold increase in M w compared to buffer alone. These findings highlight the advantageous role of ethanol as a medium to obtain lignin units with high molecular weight.	
Palavras-Chave: 	Electric conduction; Kraft lignin; Laccase polymerisation; Lignin polymerisation.	
Thesagro: 	Etanol; Lignina.	
Thesaurus Nal: 	Antioxidants.	
Categoria do assunto: 	K Ciência Florestal e Produtos de Origem Vegetal	
Registro original: 	Embrapa Florestas (CNPF)	
Exemplares: 	CNPF - (58936-1) - UPC - AP - DD -  -  -  - DIS