The Effects of CO2 Laser Irradiation on Color and Major Chemical Component Changes in Hardwoods

Ivan Kubovsky, Frantisek Kacik, Veronika Velkova

Abstract


The influence of laser radiation was evaluated relative to the color and major chemical component changes of three hardwood species. The surfaces of maple (Acer pseudoplatanus L.), beech (Fagus sylvatica L.), and lime (i.e. linden, Tilia vulgaris) wood were exposed to radiation from a CO2 laser (wavelength = 10.6 µm, output power = 45 W). It was observed that increased doses of irradiation resulted in a decrease in the lightness (L*), increase in the total color difference, and a drop in the total polysaccharide content. Compared with the non-irradiated specimens, the ΔL* values at the highest irradiation doses were −56 (maple), −46.8 (beech), and −50.5 (lime). The trends observed in the FTIR spectra also showed there was a relationship between the breaking of C=O and C=C bonds in important functional groups in the lignin, hemicellulose, and carbohydrates. A highly linear correlation (R2 from 0.902 to 0.987) was observed between the increase in the ΔL* and decrease in the hemicellulose content, which degrades faster than other basic wood components. Such a phenomenon may have been related to the formation of new chromophore structures, which caused the color changes in the wood.

Keywords


Maple; Beech; Lime wood; Laser irradiation; Color; Saccharides

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Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126