From hydrophilic to hydrophobic wood using direct fluorination: A localized treatment

Publication date: Available online 24 April 2018Source: Comptes Rendus ChimieAuthor(s): Martial Pouzet, Marc Dubois, Karine Charlet, Alexis BéakouAbstractWhen controlled by the treatment duration or the quantity of reactive molecules, direct fluorination using F2 gas is efficient to decrease the hydrophilicity of wood both in the form of massive piece and powder. To prove that silver fir pieces and wood flour (mix of spruce and silver fir species) were investigated as representative examples. In both the cases, hydroxyl groups are converted into CF bonds resulting in the decrease in affinity for water. Fluorination is mainly located in the outer parts of the wood cell, where the content of lignin is the highest, maintaining the inner ones nonmodified. Because the microstructure is maintained by this location of fluorination, the mechanical properties are conserved for silver fir pieces. The mechanical properties are even enhanced for composite containing fluorinated wood flour because of a better compatibility between the fluorinated fillers and the polyester matrix.RésuméLorsque la durée de traitement ou la quantité de molécules réactives est contrôlée, la fluoration directe en utilisant le fluor moléculaire F2 s'avère efficiente pour faire décroître l'hydrophilie du bois, à la fois sous forme de pièces massives et de poudre. Pour mettre en évidence cet effet, des morceaux de sapin et de la farine de bois ont été fluorés à titre d'exemples significatifs. ...

Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research