Efeito do intemperismo artificial em quatro madeiras tropicais monitorado por espectroscopia de infravermelho (DRIFT)
AUTOR(ES)
Pastore, Tereza Cristina Monteiro, Oliveira, Cynara Caroline Kern de, Rubim, Joel Camargo, Santos, Kelly de Oliveira
FONTE
Química Nova
DATA DE PUBLICAÇÃO
2008
RESUMO
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.
Documentos Relacionados
- RESISTÊNCIA AO INTEMPERISMO ARTIFICIAL DE QUATRO MADEIRAS TROPICAIS: O EFEITO DOS EXTRATIVOS
- RESISTÊNCIA AO INTEMPERISMO ARTIFICIAL DE CINCO MADEIRAS TROPICAIS E DE DOIS PRODUTOS DE ACABAMENTO
- Colorimetria e espectroscopia no infravermelho médio em madeira de curupixá frente ao intemperismo artificial com produtos de acabamento
- CARACTERIZAÇÃO DO ATAQUE DE FUNGOS APODRECEDORES DE MADEIRAS ATRAVÉS DA COLORIMETRIA E DA ESPECTROSCOPIA DE INFRAVERMELHO
- Sistema tutor monitorado por rede neural artificial