THERMAL TREATMENTS FOR THE COLORIMETRIC STABILIZATION OF TROPICAL HARDWOOD / Aplicação de tratamentos térmicos para estabilização colorimétrica de madeiras tropicais

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Three tropical wood species, Simarouba amara, Sextonia rubra and Cariniana micrantha, were submitted to four thermal treatments aiming to improve the resistance to photo degradation after 84 hours of ultraviolet irradiation. The treatments were: I - one hour at 150C; II - two hours at 150C; III - one hour at 200C; IV - two hours at 200C. The non-destructive technique known as DRIFT was used to compare the chemical changes of the wood components. The thermal modification was carried out in a common laboratory oven with air circulation at atmospheric pressure and without gas control. The colorimetric parameters of the CIELAB 1976 system: L*, a*, b*, C e h* were measured and the colorimetric variation calculated: L, a, b e E. After the application of the thermal treatments the greatest changes in color occurred with samples treated at two hours at 200C (Treatment IV). The study of the DRIFTs spectra showed that all wood specimens lost water and a migration of the extractives to the woods surface took place. After the ultraviolet irradiation period, Simarouba amara changed under treatment III and Sextonia rubra specimens were modified under treatment II, showing better performances as compared with the control samples. The thermal modification of Cariniana micrantha did not produced any improvement in the wood samples

ASSUNTO(S)

infravermelho drift estabilização engenharias colorimetria tratamento térmico

ACESSO AO ARTIGO

Documentos Relacionados