Synthesis and characterization of methylcellulose produced from bacterial cellulose under heterogeneous condition

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MetadadosDescriçãoIdioma
Autor(es): dc.contributorUniversidade Estadual Paulista (UNESP)-
Autor(es): dc.creatorOliveira, Rafael L.-
Autor(es): dc.creatorVieira, Júlia G.-
Autor(es): dc.creatorBarud, Hernane S.-
Autor(es): dc.creatorAssunção, Rosana M. N.-
Autor(es): dc.creatorFilho, Guimes R.-
Autor(es): dc.creatorRibeiro, Sidney J. L.-
Autor(es): dc.creatorMessadeqq, Younes-
Data de aceite: dc.date.accessioned2021-03-11T00:51:38Z-
Data de disponibilização: dc.date.available2021-03-11T00:51:38Z-
Data de envio: dc.date.issued2018-12-11-
Data de envio: dc.date.issued2018-12-11-
Data de envio: dc.date.issued2015-09-01-
Fonte completa do material: dc.identifierhttp://dx.doi.org/10.5935/0103-5053.20150163-
Fonte completa do material: dc.identifierhttp://hdl.handle.net/11449/177488-
Fonte: dc.identifier.urihttp://educapes.capes.gov.br/handle/11449/177488-
Descrição: dc.descriptionIn this work, methylcellulose (MC) was produced from bacterial cellulose (BC), using dimethyl sulfate in a 3 h (MC3h) or 5 h (MC5h) reaction under heterogeneous conditions, with reagent substitution at each hour. MC3h showed a degree of substitution (DS) of 2.26 ± 0.13 and MC5h showed a DS of 2.33 ± 0.05. The two samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), differential thermal analysis (DTA), thermal gravimetric analysis (TGA), <sup>13</sup>C nuclear magnetic ressonance (NMR) and <sup>1</sup>H NMR techniques. The FTIR spectra of the BC and MC samples present significant differences in the regions from 3750 to 2750 cm<sup>-1</sup> and from 1500 to 750 cm<sup>-1</sup>, which evidence the methylation of the samples. Solid state NMR spectroscopy of the MC samples was used to identify the <sup>13</sup>C NMR signals of substitution at sites C-2, C-3 or C-6 in the glucopyranose units. The modification of bacterial cellulose produced a material with a high DS, determined by three different techniques (chemically and using the liquid <sup>1</sup>H and solid <sup>13</sup>C NMR spectra). These samples also demonstrate high crystallinity and thermal stability. With the MC samples synthesized in this work, transparent and resistant films were prepared and also a highly porous sponge like material.-
Formato: dc.format1861-1870-
Idioma: dc.languageen-
Relação: dc.relationJournal of the Brazilian Chemical Society-
Relação: dc.relation0,357-
Relação: dc.relation0,357-
Direitos: dc.rightsclosedAccess-
Palavras-chave: dc.subjectBacterial cellulose-
Palavras-chave: dc.subjectCellulose derivatives-
Palavras-chave: dc.subjectFTIR-
Palavras-chave: dc.subjectMethylcellulose-
Palavras-chave: dc.subjectNMR spectroscopy-
Palavras-chave: dc.subjectTGA/DTA-
Título: dc.titleSynthesis and characterization of methylcellulose produced from bacterial cellulose under heterogeneous condition-
Tipo de arquivo: dc.typelivro digital-
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