Portal de Periódicos da CAPES

Artigo Acesso aberto Produção Nacional Revisado por pares

BIBTEX RIS

Synthesis and Characterization of Methylcellulose Produced from Bacterial Cellulose under Heterogeneous Condition

2015; Brazilian Chemical Society; Linguagem: Inglês

10.5935/0103-5053.20150163

1678-4790

Rafael L. Oliveira, Júlia Graciele Vieira, Hernane da Silva Barud, Rosana Maria Nascimento de Assunção, Guimes Rodrigues Filho, Sidney J. L. Ribeiro, Younes Messadeqq,

Lignin and Wood Chemistry

In 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), 13 C nuclear magnetic ressonance (NMR) and 1 H NMR techniques.The FTIR spectra of the BC and MC samples present significant differences in the regions from 3750 to 2750 cm -1 and from 1500 to 750 cm -1 , which evidence the methylation of the samples.Solid state NMR spectroscopy of the MC samples was used to identify the 13 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 1 H and solid 13 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.