WOOD RESEARCH Volume 69, Number 3, 2024
MERYEM KACMAZ UNVER, MUSTAFA ALTUNOK, and SEKIP SADIYE YASAR

THE INVESTIGATION OF NATURAL AGING BEHAVIOR OF SOME WOOD SPECIES MODIFIED WITH NATURAL PRESERVATIVES

This study evaluates the effects of 12-month outdoor weathering on Scots pine (Pinus sylvestris L.) and sessile oak (Quercus petraea L.) woods modified with tannins. Wood specimens were divided into four groups: Group A (control, natural aging (NA)), Group B (NA + 100% walnut tannin (WT)), Group C1 (NA + 50% WT and 50% pine tannin), and Group C2 (NA + 50% WT and 50% oak tannin). Group A showed density decreases of 4.3% for Scots pine and 4.7% for sessile oak, while Group B samples exhibited density increases of 2.6% and 1.6%, respectively. Group A specimens had hardness losses of 36.3% for Scots pine and 28.7% for Sessile oak, compared to reduced losses of 8.8% and 11.2% in Group B. Bending strength and modulus of elasticity also decreased significantly in Group A but were minimally affected in Group B. These results indicate that tannin treatments, particularly walnut tannin, improve wood durability and mechanical performance, offering an eco-friendly alternative to conventional treatments

WOOD RESEARCH Volume 65, Number 1, 2020
Petar Antov, Viktor Savov, and Nikolay Neykov

Sustainable bio-based adhesives for eco-friendly wood composites. A review

The aim of the present review is to summarize the current state of research in the field of sustainable bio-based adhesives used for production of eco-friendly wood composite materials. The article is focused mainly on the use of lignin, starch and tannins as raw materials and alternatives to the existing conventional adhesives. It is expected that increased amounts of bio-based adhesives will be used in the production of wood composites in order to meet the current needs for development of sustainable and innovative materials which will make the wood-based panel industry more sustainable and lower its dependence on fossil fuels. However, there are still substantial challenges for the complete replacement of petroleum-based wood adhesives with bio-based adhesives, mainly because of their relatively poor water resistance, low bonding strength and large natural variations due to different growing conditions. In this respect, fundamental research is still need in order to determine the factors for formulating bio-based adhesives with optimal properties and broaden their application in wood-based panel industry.