Akademik Veri Yönetim Sistemi
BioResources, cilt.20, sa.4, ss.10823-10837, 2025 (SCI-Expanded, Scopus)
The adhesion strength was studied for water-based nano-varnishes applied to densified and thermally post-treated beech (Fagus orientalis L.) and pine (Pinus sylvestris L.) woods. Specimens were thermo-mechanically densified at different compression ratios (20% and 40%) and temperatures (110 °C and 150 °C), and subsequently thermally treated at 190, 200, and 210 °C. One-component (OWB) and two-component (TWB) nano-varnishes were applied, and adhesion strength was evaluated using the pull-off test. Results revealed that the modification processes greatly influenced adhesion, with distinct effects depending on wood species. For untreated beech, densification improved adhesion strength, whereas for pine, it either reduced or did not cause a pronounced change. A primary finding was that thermal treatment decreased adhesion strength for all specimens in a temperature-dependent manner; higher temperatures led to progressively lower adhesion. This decline was more pronounced in densified specimens (especially beech wood). The reason was attributed to the cohesive failure within the weakened wood substrate rather than adhesive failure at the varnish-wood interface. Across all treatment conditions, TWB varnish exhibited superior adhesion compared to OWB. The study concluded that densification may have a species-specific effect, while thermal treatment fundamentally reduces wood surface strength and, consequently, varnish adhesion.