| Popis: |
Le traitement thermique superficiel du bois permet de rehausser ses proprietes hydrophobe, antifongique et anti-gonflement contribuant a le mettre a l'abri des aleas naturels. Nous avons etudie la pertinence d'un traitement solvothermique d'eprouvettes de bois d'epinette noire impregnees de liquides ioniques hydrophile ([EMIM][OTf]) et hydrophobe ([HMIM][TF2N]) comparativement a un traitement thermique simple sous balayage a l'azote. Les eprouvettes ont ete soumises a des tests d'adsorption d'humidite, d'absorption d'eau, de gonflement, et de proprietes mecaniques apres des traitements realises dans les gammes de temperature et de temps suivantes: [180 °C–260 °C] et [30 min–4 h]. Les tests ont montre une diminution notable de la teneur ultime en humidite et de prise d'eau liquide lorsque les echantillons de bois sont prealablement impregnes de liquide ionique hydrophobe et que la temperature de traitement reste inferieure a 200 °C. Cependant, les tests de proprietes mecaniques ont montre que les modules d'elasticite et de rupture des eprouvettes affichaient une tendance a la baisse avec l'augmentation de la temperature et du temps de traitement. L'impregnation de liquide ionique ne changeait rien a ce comportement meme si en general une fragilisation accrue des eprouvettes pouvait etre notee a cause de la solubilisation partielle des principaux composants de bois. Surface heat treatment of wood improves its hydrophobic, antifungal, and anti-swelling properties, and strengthens its resistance to the vagaries of natural exposure. We investigated the relevance of a superficial solvothermal treatment of wood specimens impregnated with hydrophilic ([EMIM][OTf]) and hydrophobic ([EMIM][OTf]) ionic liquids which we compared to a conventional heat treatment under nitrogen atmosphere over the following treatment temperature and time ranges: [180 °C – 260 °C] and [30 min – 4 h]. The treated specimens were subjected to moisture adsorption, water absorption, swelling, and mechanical properties testing. The results revealed a notable decrease in ultimate moisture content and water uptake of the samples, provided they were impregnated with a hydrophobic ionic liquid before heat treatment at temperatures less than 200 °C. However, the mechanical properties testing showed that the elastic and rupture moduli of specimens decreased with increasing treatment temperature and time irrespective of using ionic liquids. However, the impregnated samples suffered in general increased breakability which was ascribed to partial solubilization of wood components in the ionic liquid. |
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