Distribution and penetration of the tung oil in wood studied by high-resolution magnetic resonance imaging
IRG/WP 16-20593
M Žlahtič, U Mikac, I Serša, M Merela, M Humar
Water repellents as environment-friendly treatments are gaining their popularity as non-biocidal solutions for wood protection. One of the most important water repellents for wood besides waxes and organosilicon compounds are drying oils. Tung oil is one of the best performing oil. However, tung oil, similarly as other oils, does not penetrate deeply into wood, due to its high viscosity. In order to improve penetration of oil into wood, vacuum-pressure procedure was applied. Species chosen for this study are important in Central Europe, namely, sweet chestnut heartwood, European larch heartwood, Scots pine heartwood and sapwood, and Norway spruce heartwood wood. Distribution of oil in wood after treatment was measured by magnetic resonance imaging (MRI), which was already being successfully applied in wood science. The aim was to employ the MRI technique to elucidate influence of treatment method and wood species on distribution and penetration of tung oil. MR imaging was found suitable method for observation of oil penetration as well. What is more, if the intensity of signal is high enough, the MR imaging revealed not only intensity of the signal, but also distribution and the shape of specimens. Also early-wood and late-wood areas can be seen. In sweet chestnut traheids can be seen through whole specimens.