Yu Hai-Xia, Pan Xin, Xu Man-Ping, Yang Wei-Ming, Wang Jin, Zhuang Xiao-Wei
Zhejiang Academy of Forestry (Zhejiang Provincial Key Laboratory of Biological and Chemical Utilization of Forest Resources), 399# Liuhe Road, Xihu District, Hangzhou, Zhejiang 310023, People's Republic of China.
Zhejiang Forestry Product Testing Station, 399# Liuhe Road, Xihu District, Hangzhou, Zhejiang 310023, People's Republic of China.
R Soc Open Sci. 2018 Jun 20;5(6):180110. doi: 10.1098/rsos.180110. eCollection 2018 Jun.
Photodegradation is one of the key factors that affect bamboo material application in the exterior environment. Photo radiation will cause chemical degradation, discoloration and cracks on the bamboo surface, thus resulting in weakened strength. The study imitated the accelerated weathering effect of Moso bamboo in sunlight by using UV 313 light. Results showed that after UV irradiation, lignin content decreased sharply. Lignin degradation products are commonly rich in double bonds conjugated with benzene rings; they absorb UV light and shift surface spectral absorbency from the visible to the UV region and play an important role in the first stage of reddish-yellow discoloration. The photochemical reactions were very rapid at the beginning and then slowed down after one week. The degraded products covered the surface and protected the inner layer from further degradation. The surface colour turned grey and lighter with erosion of degradation products when the experimental time was extended.
光降解是影响竹材在室外环境中应用的关键因素之一。光辐射会导致竹材表面发生化学降解、变色和开裂，从而使强度降低。该研究通过使用UV 313光模拟毛竹在阳光下的加速老化效果。结果表明，紫外光照射后，木质素含量急剧下降。木质素降解产物通常富含与苯环共轭的双键；它们吸收紫外光并使表面光谱吸收从可见光区域转移到紫外区域，在红黄变色的第一阶段起重要作用。光化学反应在开始时非常迅速，一周后减缓。降解产物覆盖在表面，保护内层免受进一步降解。随着实验时间的延长，降解产物被侵蚀，表面颜色变灰且变浅。
