Slabejová Gabriela, Vidholdová Zuzana, Šmidriaková Mária
Faculty of Wood Sciences and Technology, Department of Furniture and Wood Products, Technical University in Zvolen, 960 01 Zvolen, Slovakia.
Faculty of Wood Sciences and Technology, Department of Wood Technology, Technical University in Zvolen, Masaryka 24, 960 01 Zvolen, Slovakia.
Polymers (Basel). 2023 Aug 5;15(15):3313. doi: 10.3390/polym15153313.
This paper deals with the influence of dark and light exposure on the colour change of a transparent two-component polyurethane surface finish. The surface finish with polyacrylic and aldehyde resin was applied to the surfaces of untreated and hydrothermally treated European beech, alder, Norway maple, and Paper birch wood. The test specimens were deposited indoors for 60 days. The colour values (lightness L*, redness + a*, yellowness + b*, chroma C*, hue angle h°) were expressed in the CIELAB system. The results showed that the colour difference of the finish surfaces of all hydrothermally treated wood species was 27-50% lower after the dark than when exposed to light. In the case of finished untreated wood, the colour difference was 51-73% lower after the dark than light exposure. Only the finished untreated and hydrothermally treated Norway maple wood surfaces showed similar and significant changes after both dark and light exposure. The lower value of the colour difference of the finished hydrothermally treated wood was due to the fact that steaming wood with saturated water steam has a positive effect on the overall colour stability of the finish and partial resistance to the initiation of photolytic reactions caused by light.
本文探讨了光照和黑暗暴露对一种透明双组分聚氨酯表面涂层颜色变化的影响。将含有聚丙烯酸和醛树脂的表面涂层涂覆在未经处理和经过水热处理的欧洲山毛榉、桤木、挪威枫木和纸桦木表面。测试样品在室内放置60天。颜色值（明度L*、红度+a*、黄度+b*、色度C*、色相角h°）采用CIELAB系统表示。结果表明，所有经过水热处理的木材品种，涂层表面在黑暗环境下的色差比光照后低27 - 50%。对于涂覆有涂层的未经处理的木材，黑暗环境下的色差比光照后低51 - 73%。只有涂覆有涂层的未经处理和经过水热处理的挪威枫木表面在光照和黑暗暴露后显示出相似且显著的变化。经过水热处理的木材涂覆后色差较低的原因是，用饱和水蒸气对木材进行蒸煮对涂层的整体颜色稳定性有积极影响，并对由光引发的光解反应具有部分抗性。
