Studio degli effetti di protettivi del legno dalla fotodegradazione mediante misure di colore e spettroscopia FTIR
Author(s)
Balletti, Federica
Date Issued
June 27, 2016
Type
Doctoral Thesis
Abstract
During the present study we monitored the light radiation effects on poplar (Populus L. sp) wood, an important material both in industrial and in cultural heritage field.
We studied the superficial alteration of poplar wood samples exposed to artificial irradiation in a controlled environment for a total exposure time of 1008 hours.Light radiation causes photochemical oxidation of the surface layers of wood, with a consequent alteration of the colour, so both the wood colour changes and its chemical composition changes has been studied.
Peculiar aim of the study has been the comparison between changes in the surface of non-treated wood samples with changes recorded on samples which have been covered by slides treated with two natural origin substances (beeswax and shellac) and with a preservative substance (Linfoil®).
Colour changes and chemical degradation have originated statistically significant regression functions.In the second part of the experiment, it was investigated the effect of laser irradiation on poplar wood (Populus sp. L.) natural and treated with shellac and beeswax. The wood samples treated with shellac and beeswax were subjected to aging with artificial light radiation in a controlled environment through the Solar Box. Subsequently they were treated with laser irradiation. To understand the color variation of the wood, and the changes in the content of chemical elements were performed color measurement with CIELAB (parameters L * a * b *) method, and analysis of peak intensities of spectrums FT-IR wavelengths that identify the chemical components on the wood surface. Statistical analysis of the differences in the state of color before treatment and after various laser treatments showed that all treatments are statistically different and also showed that after irradiation treated wood with shellac has undergone changes in color but was not restored the "natural wood" condition and the state "initial treatment with shellac and wax" condition. FT-IR highlighted that after the laser irradiation lignin has undergone degradation.
Additional information
Dottorato di ricerca in Scienze e tecnologie per la gestione forestale e ambientale
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