Humins are heterogeneous and polydisperse furanic macromolecules derived from sugar biorefinery. Improving wood properties by humination has become of interest recently. This study examined the photodegradation stability of European pine sapwood microveneers modified with humins at different concentrations of citric acid (CA) and succinic acid (SA) as reaction catalysts, e.g., 1.5 %, 3 %, and 4.5 % wt.%. The photostability of huminated wood was assessed after 48 h, 96 h, and 144 h of exposure to the accelerated weathering test by means of mass loss and finite-span tensile strength. The results were compared with unmodified and also unweathered samples. The FT-IR spectroscopy showed apparent changes in the chemical structure of wood by humination modifications. The weight percentage gains of the samples increased with increasing the concentration of the catalyst. While no differences were observed between the samples after two weeks of the water leaching. The strength losses of weathered microveneers were, however, mostly reduced by humin-based formulas containing catalysts, where the microveneers modified with 1.5 % and 3 % CA showed respectively 32 % and 41 % lower strength loss values than the unmodified samples after 144 h of weathering. Overall, the results showed a high potential for humins to protect wood against photodegradation.

中文翻译：

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腐植欧洲松 (Pinus sylvestris L.) 微单板的光降解稳定性

腐殖质是来自糖生物精炼厂的异质且多分散的呋喃大分子。最近，通过腐殖质改善木材性能已引起人们的兴趣。本研究考察了以不同浓度的柠檬酸 (CA) 和琥珀酸 (SA) 作为反应催化剂（例如 1.5%、3% 和 4.5% wt.%）的腐殖质改性的欧洲松边材微单板的光降解稳定性。在暴露于加速风化试验 48 小时、96 小时和 144 小时后，通过质量损失和有限跨度拉伸强度评估腐殖木材的光稳定性。将结果与未改性和未风化的样品进行比较。傅立叶变换红外光谱显示，腐殖质改性使木材的化学结构发生了明显的变化。样品的重量百分比增益随着催化剂浓度的增加而增加。虽然水浸两周后，样品之间没有观察到差异。然而，风化微单板的强度损失主要是通过含有催化剂的胡敏素配方来降低的，其中用 1.5% 和 3% CA 改性的微单板在 144 小时的老化后，强度损失值分别比未改性的样品低 32% 和 41%。风化。总体而言，结果表明腐殖质具有保护木材免受光降解的巨大潜力。