Investigation of the effect of heat treatment and nanoparticles on wettability and transparent adhesion resistance of lacquer coating

In this study, the effect of silica nanoparticles and heat treatment of beech (Fagus orientalis),walnut (Juglans regia) and spruce (Picea abies) wood species on adhesion strength, drop contact angle and water absorption of clear coating lacquer were studied. For this purpose, samples with 8% moisture and 200 × 100 × 20 mm were prepared. The wood samples were heat treated in oven at different temperatures of 160 and 180 °C for 3 hours. After finishing the treatment, the surface finish of the specimens was 120 and 180, respectively. Transparent lacquer folders containing 0, 0.5, 1 and 1.5% silica nanoparticles were used to cover the samples. The results showed that heat treatment increased the drop contact angle and the adhesion strength of the coating and increased the temperature of the drop contact angle treatment and the adhesion strength as well. Thermal treatment at 180 °C with coating containing 1% nano and lowest drop contact angle was observed in control samples. Wood samples treated with walnut at 160 ° C and containing 1% nano coating had the highest adhesion resistance. The water uptake of treated wood samples decreased compared to the untreated samples in all three species and this trend continued with the increase of nanoparticles in the coating so that the walnut control samples had the highest water uptake at 180 °C. and 1% nano coatings were the lowest water absorption in spruce.