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Advisor(s)
Abstract(s)
Extractive-free cork from Quercus suber L. was submitted to organosolv fractionation and the effects
of different process variables, such as ethanol/water ratio, temperature, time and the presence of acidic
or alkaline catalysts, were studied. The variation of the relative proportions of extracted components, as
a function of the processing conditions, could thus be established. Whereas the addition of 0.1 M acetic
acid only increased the yield of extracted materials from about 15 to 23%, the use of sodium hydroxide,
at the same concentration, produced a jump to 76%. In the case of the alkaline organosolv fractiona tion, an increase in process temperature, time and catalyst concentration led to an increase in the
extraction yield, although in some cases this increase did not follow a sustained trend, as in the case of
reaction time. Increasing the ethanol/water ratio led to a higher selectivity in favour of suberin
extraction. Residual cork from different organosolv processes was characterised by FTIR and 13C
solid-state NMR. The latter technique provided some valuable information about both process
selectivity and cork morphology, particularly with respect to the positioning of suberin macromolecules
in the cell wall.
Description
Keywords
Cork Quercus suber L. Organosolv fractionation Ethanol/water extraction Suberin FTIR 13C NMR . Faculdade de Ciências Exatas e da Engenharia
Citation
Cordeiro, N., Neto, C. P., Rocha, J., Belgacem, M. N., & Gandini, A. (2002). The organosolv fractionation of cork components. Holzforschung, 56(2), 135-142.
Publisher
De Gruyter