Abstract Drying oils provide exquisite bio-based finishes for wood products but their application is restricted by their time-consuming polymerization. Research and industrial development are impeded by a lack of scientific methods to follow the polymerization progress of oils applied on wood. We investigated the drying behavior of linseed oil, tung oil, and their 1:1 mixture both with and without the addition of a drier. Liquid samples revealed faster polymerization of the mainly conjugated and highly unsaturated tung oil than of non-conjugated linseed oil. Recurring water contact angle measurements of oil finishes applied on beech and oak wood showed clear differences in wetting. Tung oil provided hydrophobicity to all wood samples soon after its application, even when used without drier. Linseed oil required longer drying times and was more susceptible to substrate influences but ultimately reached the highest contact angles when equipped with a drier. Further, we observed a relationship between drying time and contact angle stability. As a new and straightforward tool to characterize the drying progress of applied oil-based finishes, we propose the calculation of a contact angle reduction factor, that takes into account both the initial water contact angle as well as its stability over measurement time.

中文翻译：

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用于实木涂饰的天然油的干燥行为

摘要 干性油为木制品提供了精美的生物基饰面，但其应用受到其耗时聚合的限制。由于缺乏科学方法来跟踪应用于木材的油的聚合过程，研究和工业发展受到阻碍。我们研究了亚麻籽油、桐油及其 1:1 混合物在添加和不添加催干剂的情况下的干燥行为。液体样品显示主要共轭和高度不饱和桐油比非共轭亚麻籽油的聚合速度更快。对应用于山毛榉和橡木的油性饰面进行反复的水接触角测量，表明润湿性存在明显差异。桐油在使用后不久就为所有木材样品提供了疏水性，即使在没有干燥剂的情况下使用也是如此。亚麻籽油需要更长的干燥时间，更容易受到底物的影响，但在配备干燥器时最终会达到最高的接触角。此外，我们观察到干燥时间和接触角稳定性之间的关系。作为表征应用油基饰面干燥过程的一种新的、直接的工具，我们建议计算接触角减小系数，该系数考虑了初始水接触角及其随测量时间的稳定性。