Effect of artificial weathering on tropical woods monitored by infrared spectroscopy (DRIFT)

Química Nova

Santos, Kelly de Oliveira¹  Universidade de Brasília, Brasília, Brasil¹  Serviço Florestal Brasileiro, Brasília, Brasil¹  Pastore, Tereza Cristina Monteiro¹  Universidade Federal de Santa Catarina, Florianópolis, Brasil¹  Rubim, Joel Camargo¹  Oliveira, Cynara Caroline Kern de¹ 

关键词: DRIFT;    weathering;    tropical wood.;   

DOI  :  10.1590/S0100-40422008000800030

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

Four tropical woods, were investigated to compare their performance and natural resistances to artificial weathering using the diffuse reflectance infrared Fourier transform spectroscopy (DRIFT). The species were garapeira (Apuleia leiocarpa), itaúba (Mezilaurus itauba) and tauari (Couratari sp.), woods traditionally indicated for exterior uses, and marupá (Simarouba amara), that served as reference. The samples were submitted to cycles of UV radiation (350 nm) and water until 2,000 h. The photodegradation processes of woods surfaces were accomplished monitoring the changes in the intensities associated to lignin (1508 cm-1) and carbonyl group (1736 cm-1) absorptions. The results have shown that lignin was the first component to be photodegradated, resulting in surfaces mainly composed by cellulose, after 2,000 h of UV irradiation. The processes of formation and lixiviation of carbonyl compounds were different for each species. The experimental conditions used in this work were too severe to evaluate the wood density and extractives content influences during the treatment.

【 授权许可】

Unknown