Investigation of Adhesion Strength of Alkyd and Nitro Cellulose Transparent Coatings in Different Heat-treated Poplar Wood

The main purpose of current research was to investigate the adhesion strength of transparent coatings of thermally modified poplar wood in different mediums before and after accelerated aging. Specimens of 150×100×20 mm were prepared and thermally modified in different mediums (air, steam, steam and press, linseed oil) in 150 and 180 °C. Untreated and modified specimens were coated with acid catalyzed lacquer and nitrocellulose lacquer. Adhesion strength of coatings were analyzed before and after accelerated aging. The results showed that thermal modification in hot air and hot steam, affect positively on coating adhesion strength before and after aging test. The best results observed in hot steam in 150 °C. As temperature of thermal modification elevated, adhesion strength of coatings decreased. Specimens coated with nitrocellulose lacquer had higher adhesion strength. Based on revealed results, it can be concluded that adhesion strength of thermally modified wood depends on coating type, thermal modification medium and aging process.