【摘要】 【目的】探究温度、紫外光波长和有无淋雨对红木材松颜色的影响及其规律，为户外木制品的光老化防护提供理论基础。【方法】采用人工老化试验箱，根据温度（30℃和60℃）、紫外光波长（340 nm和351 nm）和有无淋雨设置4组人工老化条件（T1:30℃+UVA340;T2:60℃+UVA340;T3:60℃+UVA351;T4:60℃+UVA340+雨），分析人工老化条件对红松木材构造、化学组分和颜色的影响及其规律，探讨化学组分与颜色的相关性，明确不同老化条件引起颜色差异的原因。【结果】木材表面粗糙度随人工老化时间延长而增加。高温、低紫外光波长或淋雨均会加剧木材表面结构降解，引起木材表面粗糙度增加。经720 h紫外光辐照后，T1、T2、T3、T4条件下木材表面粗糙度分别提升18.32%、43.33%、41.99%和193.36%。显微结构分析表明，单纯紫外光辐照条件（T1、T2、T3）下细胞结构保持完整；增设淋雨（T4）会导致细胞壁塌陷、胞间层连接失效及木射线变薄等结构劣化。在表观上，人工老化后木材表面呈现出不同程度黄变或褐变。通过CIE颜色系统量化可知，在无淋雨条件（T1、T2、T3）下，木材的L^*单调降低、a^*和b^*单调增加；增设淋雨（T4）后，L^*、a^*和b^*变化复杂，720 h老化后L^*、a^*和b^*均降低。对比不同人工老化条件发现，温度和淋雨对L^*、a^*和b^*影响显著，紫外光波长主要影响a^*。总色差ΔE^*分析表明，人工老化条件的影响程度为淋雨最大、温度次之、紫外光波长相对较小。利用红外光谱中木质素/碳水化合物特征峰强度比值R(I_{1 506}/_{1 372})和羰基/碳水化合物特征峰强度比值R(I_{1 734}/_{1 372})量化人工老化过程中木质素和羰基相对含量变化，随着老化时间延长，木质素含量降低、羰基含量增加；升高温度和增设淋雨均会加速光化学反应过程，淋雨的影响更显著。通过建立R(I_{1 506}/_{1 372})和R(I_{1 734}/_{1 372})与ΔE^*的相关联系，发现ΔE^*与R(I_{1 506}/_{1 372})呈负相关关系，与R(I_{1 734}/_{1 372})呈正相关关系。【结论】老化条件对木材表面粗糙度的影响程度依次为淋雨>温度>紫外光波长，增设淋雨会使木材细胞壁发生明显降解。针对表观颜色而言，无淋雨条件下表现为暗化、偏红、偏黄特征，增设淋雨条件后表观总体呈现暗化、偏绿、偏蓝的趋势。老化条件对木材总色差的影响程度依次为淋雨>温度>紫外光波长。通过建立化学组分含量和总色差的数量关系，证实人工老化过程中木材表观颜色与木质素的降解和羰基的生成之间存在密切关联。更多还原

【Abstract】 【Objective】This study aims to investigate the effects of temperature, ultraviolet（UV） wavelength, and water on the color changes of Korean pine under artificial weathering, so as to provide a theoretical basis for the photoaging protection of outdoor wood products.【 Method】 Using weathering tester, four artificial weathering conditions were established based on temperature（30 ℃ and 60 ℃）, ultraviolet radiation A wavelength（UVA340 nm and UVA351 nm）, and water: T1: 30 ℃ + UVA340; T2:60 ℃ + UVA340; T3: 60 ℃ + UVA351; T4: 60 ℃ + UVA340 + rain. The structure, chemical composition, and color of Korean pine were analyzed during artificial weathering. The correlation between chemical composition and color was explored as well.【Result】 The surface roughness of the wood increased with prolonged artificial aging. High temperature, lower UVA wavelength, or the presence of water exacerbated the degradation of the wood surface, leading to high roughness. After 720 h of UVA irradiation, the roughness of samples under conditions T1, T2, T3, and T4 increased by 18.32%, 43.33%, 41.99%, and 193.36%, respectively. Cell structures remained intact under pure UVA irradiation conditions（T1, T2, T3）. However, the addition of water（T4） caused significant structural deterioration, including cell wall collapse, failure of intercellular middle lamella, and thinning of wood rays. In terms of appearance, the wood surface exhibited varying degrees of yellowing or browning after artificial weathering. Quantification using the CIE color system showed that under non-water conditions（T1, T2, T3）, the L^* value decreased and the a^*, b^* values increased monotonically. The addition of water led to complex changes in L^*, a^* and b^* values. Comparative analysis of different aging conditions indicated that temperature and water significantly affected L^*, a^* and b^*, while UVA wavelength primarily influenced the a^* value. Overall color change（ΔE^*） analysis revealed that the impact of weathering conditions followed the order: rain > temperature > UVA wavelength. The intensity ratios of lignin/carbohydrate R(I_{1 506}/_{1 372}) and carbonyl/carbohydrate R(I_{1 734}/_{1 372}) were used to quantify the relative changes in lignin and carbonyl content, respectively. With prolonged weathering, lignin content decreased while carbonyl content increased. Both elevated temperature and the addition of water accelerated the photochemical reactions, with water having a more pronounced effect. By establishing the correlation between ΔE^* and R(I_{1 506}/_{1 372}) or R(I_{1 734}/_{1 372}), ΔE^* was negatively correlated with lignin content R(I_{1 506}/_{1 372}) and positively with carbonyl content R(I_{1 734}/_{1 372}).【 Conclusion】 The influence of weathering conditions on surface roughness follows the order: rain >temperature > UVA wavelength. Microscopically, the addition of water causes significant degradation of wood cell walls. In terms of surface color, non-water conditions result in darkening, reddening, and yellowing, while the addition of water leads to an overall trend of darkening, greening, and bluing. The impact of aging conditions on ΔE^* follows the order: rain > temperature > UVA wavelength. By establishing quantitative relationships between chemical composition and ΔE^*, it is confirmed that the surface color changes are closely associated with lignin degradation and carbonyl formation.更多还原