Simultaneous Improvement of Surface Wettability and UV Resistance of Wood with Lignin-Based Treatments

Recent advancements in wood modification aim to enhance the inherent qualities of this

versatile biological material, which includes renewability, ease of processing, and thermal insulation.

This study focuses on evaluating the effectiveness of lignin as a protective agent for less durable

wood species, namely, Pinus nigra and Fagus sylvatica L. The impregnation of wood with three various

forms of lignin, such as kraft lignin, acetylated kraft lignin, and lignin nanoparticles, was carried out

using the vacuum technique at room conditions. The results showed that the treatments significantly

improve the hydrophobicity of wood surfaces, particularly in pine wood, and provide protection

against UV ageing. Additionally, the treatments contributed to the stabilisation of moisture content

at different humidity levels. Although slight colour variations were observed, their impact on the

visual appearance was minimal, and the thermal analysis confirmed enhanced thermal properties.

Additionally, plasma treatment further enhanced hydrophobicity after treatments, offering potential

benefits in terms of moisture resistance and durability. The findings of this study highlight the

promising effects of lignin-based treatments on wood properties, providing sustainable solutions

for wood protection in various sectors. However, further optimisation is needed to fully explore the

potential of lignin and lignin nanoparticles.