Use este identificador para citar ou linkar para este item: http://repositorio.ufla.br/jspui/handle/1/50811
Título: Evaluation of changes in cellulose micro/nanofibrils structure under chemical and enzymatic pre-treatments
Palavras-chave: Cellulose structure
Chemical characterization
Enzymes
Nanofibrillated cellulose
Pre-treatments
Data do documento: 2021
Editor: De Gruyter
Citação: MOULIN, J. C. et al. Evaluation of changes in cellulose micro/nanofibrils structure under chemical and enzymatic pre-treatments. Holzforschung, [S.l.], 2021.
Resumo: The objective of the present work was to evaluate the use of Raman microspectroscopy analysis to assess changes in cellulose micro/nanofibril structure from fibers subjected to different pre-treatments. Pulp fibers were pre-treated with 5 wt% NaOH for 2 h, 10 wt% NaOH for 1 h, and endoglucanase-type enzymes to improve nanofibrilation. After the pre-treatments, the fibers were mechanically fibrillated to produce cellulose micro/nanofibrils, which were made into films to be analyzed. Fibers pre-treated with 5 wt% NaOH produced 59% micro/nanofibrils with average diameter less than 30 nm, for Eucalyptus, and 46% of micro/nanofibrils, with the same diameter, for Pinus. However, the enzymatic pre-treatment was the most efficient, resulting in 83% of micro/nanofibrils for Eucalyptus and 78% for Pinus. This corroborates with the lowest values of the 1.096/2.896 ratio and degree of polymerization, indicating chain shortening in cellulose. X-ray diffraction and Raman microspectroscopy crystallinity results presented similar tendencies, with increased crystallinity caused by all pre-treatments, being 5 wt% NaOH for 2 h the highest, with 70%, for Eucalyptus and Pinus. Enzymatic pre-treatment has produced the best fibrillation and greater crystallinity. The present work has shown a reliable way of assessing cellulose structure using Raman microspectroscopy.
URI: https://www.degruyter.com/document/doi/10.1515/hf-2020-0231/html
http://repositorio.ufla.br/jspui/handle/1/50811
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