Nanostructured cellulose is a material which presents low density, high mechanical resistance, biodegradability and huge amount of material available in nature for obtaining. These nanostructures are isolated from lignocellulosic fibers, including industrial residues, reducing the environmental impact of disposal, once the incineration is the most common residue destination. However, the most applied process for cellulose isolation is by acid hydrolysis, which generates toxic residues and may degrade the cellulose structure, reducing their properties. The study of alternative routes has been developed, one of them is enzymatic hydrolysis which is a biological method and non-aggressive to environment. At this study was obtained cellulose nanostructure from wood fiber residues of <i>Pinus</i> by enzymatic hydrolysis combining acid mercerization and alkaline bleaching as pre-treatments. They were produced four samples varying the hydrolysis time by 12, 24, 48 and 72 hours. The enzymes were a combination of commercial endoglucanase and xylanase enzymes at concentration of 6% (m/m) based on pretreat cellulose. The samples were analyzed by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), scanning electronic microscopic, atomic force microscopy (AFM) and quantification of saccharides resulted from hydrolysis process. It was possible to observe that the pre-treatments acted in the lignin and hemicellulose removal from the fibers, exposing cellulose structures for following enzymatic hydrolysis. The applied methodologies shown, by DLS, that the increase in the enzyme exposition time produced smaller nanostructures up to 48 h, after that the nanostructures presented higher sizes similar to the minor time of hydrolysis. The 48 h sample present particles with hydrodynamic radius of 70 nm. The saccharides quantification shown a similar result with particle sizes, the samples with smaller sizes present a higher concentration of redactor sugars. The obtained nanostructures could be used as good reinforcement materials for nanocomposites production.<br/>

Cellulose nanostructure obtained by enzymatic hydrolysis: The effects of treatment time

253rd National Meeting (2017)

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