Thermal modification increases the service life of wood by removing or reducing a prerequisite for fungal degradation: water within the material (Hill et al., 2021). However, there is a lack of understanding of what happens within the wood, which hampers optimization of thermal modification techniques and processes. In this study, we investigate how two types of thermal treatments affect wood-water interactions in beech and Scots pine using low–field NMR (LFNMR). In the first thermal treatment process, both heating and cooling occur at high pressure in a closed process. The second process is similar, but the cooling phase occurs at atmospheric pressure, hereby allowing volatile chemicals formed during the thermal treatment to evaporate (Pohleven et al., 2019). In addition, we performed water and Soxhlet extractions on the specimens, to investigate whether the presence of such volatile components has an impact on LFNMR measurements of (thermally modified) wood.
Keywords: thermal modification, wood-water interactions, LFNMR, pH, beech, Scots pine
Authors
Liselotte De Ligne
University of Copenhagen, Denmark
Maria Fredriksson
Lund University, Sweden
Emil Engelund Thybring
University of Copenhagen, Denmark
Login to download the PDF