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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Whiskers from sisal fibers obtained under different acid hydrolysis conditions: effect of time and temperature of extraction

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Kelcilene B. R. Teodoro ; Eliangela de M. Teixeira ; Ana C. Corrêa ; Adriana de Campos ; José M. Marconcini ; Luiz H. C. Mattoso
Total Authors: 6
Document type: Journal article
Source: POLIMEROS-CIENCIA E TECNOLOGIA; v. 21, n. 4, p. 280-285, 2011.

In this work, the effects of different conditions of time and temperature, used for the preparation of whiskers from sisal, were investigated to determine the influence of experimental parameters on morphology, crystallinity and thermal stability of materials prepared. The whiskers were obtained after the bleaching of sisal raw fiber with a solution of hydrogen peroxide alkaline. The bleached fiber was submitted to the process of hydrolysis with sulphuric acid solution 60 wt. (%) under three different conditions of temperature and time of extraction: 45 °C and 60 minutes (WS45_60); 45 °C and 75 minutes (WS45_75) and 60 °C and 30 minutes (WS60_30). The whiskers were characterized as the morphology by transmission electron microscopy (MET), crystallinity (DRX), surface charge (zeta potential), sulfur content (by elemental analysis) and thermal stability by thermogravimetry (TGA). The sisal whiskers presented an average length and diameter of 210 nm and 5 nm, respectively. Due to the high agglomeration state of whiskers, differences on dimensional features could not be determined. The results showed a strong dependence on crystallinity of whiskers with temperature and time of extraction. Hydrolysis in higher temperature (60 °C) and lower extraction time (30 minutes) resulted in whiskers with good thermal stability (235 °C), higher crystallinity and preserving the crystalline structure of cellulose. (AU)

FAPESP's process: 08/08264-9 - Study of the degradation of biodegradable polymers by light, heat and microorganisms in composted soil
Grantee:Adriana de Campos Pastre
Support type: Scholarships in Brazil - Post-Doctorate