Influence of nanoparticles and olive leaf extract in polyacrylate coating on the weathering performance of thermally modified wood.

Autor: Nowrouzi, Zahra, Mohebby, Behbood, Petrič, Marko, Ebrahimi, Morteza
Zdroj: European Journal of Wood & Wood Products / Holz als Roh- und Werkstoff; Apr2022, Vol. 80 Issue 2, p301-311, 11p
Abstrakt: Ultraviolet (UV) light and water have negative effects on the surface appearance of heat-modified wood. Although thermally modified wood is dimensionally more stable than non-modified wood, high temperature and humidity variations may induce some shrinkage and swelling even in the case of modified wood. The results can be formation of cracks on the wood surface. Hence, industries move towards developing clear coats to protect modified wood. In this study, performance of a waterborne polyacrylate coating blended with additives of nanoparticles of TiO2 or ZnO as well as with 2-(2-hydroxyphenyll)-benzotriazole (BTZ) type UV-absorber, and in combination with olive leaf extract or a hindered amine light stabilizer (HALS), was studied. The influence of the mentioned additives on surface roughness and wetting properties, as well as on adhesion strength of coatings on modified thermally modified wood in outdoor exposure was investigated. The coated thermally modified wood samples were exposed to natural weathering for 12 months. In addition, specimens of coated thermally modified wood with the best natural weathering performance were exposed to accelerated weathering. The wettability study results showed that the polyacrylate coating containing TiO2 and olive leaf extract (20%), as well as BTZ and olive leaf extract (10% and 20%) exhibited the best performance during natural weathering. Surface roughness of all coated thermally modified wood was slightly increased after natural weathering. Moreover, the highest adhesion strength was determined at the polyacrylate coating with TiO2 and olive leaf extract (20%) after both natural and accelerated weathering. Thus, a positive influence of a natural antioxidant—olive leaf extract on the weathering performance of polyacrylate wood coating formulations was confirmed. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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