COLORIMETRIC AND FTIR ATR SPECTROSCOPY STUDIES OF DEGRADATIVE EFFECTS OF ULTRAVIOLET LIGHT ON THE SURFACE OF EXOTIC IPE (TABEBUIA SP.)WOOD

摘要

The objective of the study was to characterize the UV light resistance of one of the exotic wood species -ipe (Tabebuia sp) - commonly used in the furniture industry, using the colorimetric and infrared spectroscopy analyses. A softwood species, Scots pine (Pinus sylvestris L.), was also studied for comparison purposes. Based on the results obtained after 100 h of light irradiation, colour changes were found in the samples of both analysed species, but the extentand pattern of the changes differed significantly. It was observed that the ipe wood was less influenced by light in comparison with the pine wood. The total colour difference of the pine wood amounted to 14.26 and for the ipe wood to merely 1.05. The most significant changes were observed in the case of chromatic coordinate "b". Based on the infrared spectroscopic analysis, it was concluded that 340 UV irradiation yields the degradation of lignin structure. The infrared spectra gave an insight into the changes occurring in the range of carbonyl groups present in the structure of wood components and confirmed the resistance of carbohydrates to UV irradiation.