Hızlandırılmış UV Yaşlandırma ile Odunda Meydana Gelen Renk, FTIR ve Mikroskobik Değişimlerin Belirlenmesi

Year 2021, Volume: 23 Issue: 2, 536 - 544, 16.08.2021

Eser Sözen

https://doi.org/10.24011/barofd.891805

Abstract

Yağmur, güneş, rüzgâr gibi doğal şartlar ahşap malzemenin fiziksel, kimyasal ve mekanik özelliklerinde değişimlere neden olmaktadır. Bu değişimler çoğunlukla olumsuz olarak nitelendirilmektedir. Ancak, bazı durumlarda bu olumsuz değişimler doğallığı ifade etmesi veya bir sonraki işlem için gerekli olmasında dolayı tercih edilebilmektedir. Bazı mobilya ve iç mekan tasarımlarında eskitme olarak nitelendirilen ahşaplar özellikle tercih edilmektedir. Bu çalışmada, kayın (Fagus orientalis L.) odununda hızlandırılmış UV yaşlandırma testi sonrasında renk değişimi, lignin oranı ve hücre çeperinde meydana gelen değişimler incelenmiştir. Renk ölçümü, ISO 7724 (1984) standartlarına uygun olarak UV yaşlandırma testi öncesinde ve sonrasında yapılmıştır. FTIR analizi sonucunda 945-1132 absorbans değerleri arasındaki hemiselüloz ve lignin oranında kontrol örneklerine göre %14,78 azalma meydana geldiği görülmüştür. Hücre çeperinde meydana gelen değişimler SEM analizleri ile enine kesit ve teğette ayrı ayrı incelenmiştir. Enine kesitte UV sonrası kontrol örneklerine göre belirgin çatlakların oluştuğu görülmüştür. Boyuna yönde ise paranşim hücrelerinde dağılmaların olduğu saptanmıştır.

Keywords

Hızlandırılmış UV yaşlandırma, FTIR, lignin, SEM, hücre çeperi

Determination of Color, FTIR and Microscopic Changes in Wood by Accelerated UV Aging

Abstract

Natural conditions such as rain, sun, wind cause changes in the physical, chemical and mechanical properties of the wood material. These changes are often described as negative. However, in some cases, these negative changes may be preferred because they express naturalness or are necessary for the next process. In some furniture and interior designs, woods described as aging are especially preferred. In this study, color change, lignin ratio and changes in cell wall after accelerated UV aging test in beech (Fagus orientalis L.) wood were investigated. Color measurement was done before and after UV aging test in accordance with ISO 7724 (1984) standards. As a result of FTIR analysis, it was seen that there was a decrease of 14.78% in the ratio of hemicellulose and lignin between the absorbance values of 945-1132 compared to the control samples. Changes in the cell wall were examined separately in cross section and tangent by SEM analysis. Significant cracks were observed in the cross section compared to the post-UV control samples. In the longitudinal direction, it was determined that there are dispersions in the parenchyma cells.

Keywords

Accelerated UV aging, FTIR, lignin, SEM, cell wall

References

• 1. Feist, W. C., Hon, D. N. S. (1984). Chemistry of Weathering and Protection, The Chemistry of Solid Wood, American Chemical Society 1984, pp. 401–451.
• 2. Hon, D.N.S., Chang, S.T. (1984). Surface degradation of wood by ultraviolet light. Journal of Polymer Science: Polymer Chemistry Edition, 22(9), 2227-2241.
• 3. Liu, X. Y., Timar, M. C., Varodi, A. M., Sawyer, G. (2017). An investigation of accelerated temperature-induced ageing of four wood species: colour and FTIR. Wood Science and Technology, 51(2), 357-378.
• 4. Timar, M. C., Varodi, A. M., Hacibektasoglu, M., Campean, M. (2016). Color and FTIR analysis of chemical changes in beech wood (Fagus sylvatica L.) after light steaming and heat treatment in two different environments. BioResources, 11(4), 8325-8343.
• 5. Nemeth, R., Hill, C. A., Takats, P., Tolvaj, L. (2016). Chemical changes of wood during steaming measured by IR spectroscopy. Wood Material Science Engineering, 11(2), 95-101.
• 6. Cogulet, A., Blanchet, P., Landry, V. (2016). Wood degradation under UV irradiation: A lignin characterization. Journal of Photochemistry and Photobiology B: Biology, 158, 184-191.
• 7. Tolvaj, L., Faix, O. (1995). Artificial aging of wood monitored by drift spectroscopy and CIE Lab color measurements. Holzforschung, 49(5), 397-404.
• 8. Colom, X., Carrillo, F., Nogués, F., Garriga, P. (2003). Structural analysis of photodegraded wood by means of FTIR spectroscopy. Polymer degradation and stability, 80(3), 543-549.
• 9. Teacă, C. A., Roşu, D., Bodîrlău, R., Roşu, L. (2013). Structural changes in wood under artificial UV light irradiation determined by FTIR spectroscopy and color measurements–A brief review. BioResources, 8(1), 1478-1507.
• 10. Pandey, K. K., Pitman, A. J. (2003). FTIR studies of the changes in wood chemistry following decay by brown-rot and white-rot fungi. International biodeterioration biodegradation, 52(3), 151-160.
• 11. Anderson, E. L., Pawlak, Z., Owen, N. L., Feist, W. C. (1991). Infrared studies of wood weathering. Part I: Softwoods. Applied spectroscopy, 45(4), 641-647.
• 12. Lesar, B., Humar, M., Kržišnik, D., Thaler, N., Žlahtič, M. (2016). Performance of façade elements made of five different thermally modified wood species on model house in Ljubljana. In Proceedings of the World Conference on Timber Engineering, Vienna, Austria, 22–25 August 2016; ISBN 978-390303900-1. Available online: http://wcte2016.conf.tuwien.ac.at/ (accessed on 15 October 2020).
• 13. Pandey, K. K. (2005). A note on the influence of extractives on the photo-discoloration and photo-degradation of wood. Polymer degradation and stability, 87(2), 375-379.
• 14. Reinprecht, L. (2016) Wood Deterioration, Protection and Maintenance; John Wiley Sons, Ltd.: Chichester, UK, p. 376. ISBN 978-1-119-10653-1.
• 15. Hon, D.N.S.; Minemura, N. (2001).Color and discoloration. In Wood and Cellulosic Chemistry; Hon, D.N.S., Shirashi, N., Eds.; Marcel Dekker: New York, NY, USA, pp. 385–442.
• 16. Anulika, N. P., Ignatius, E. O., Raymond, E. S., Osasere, O. I., Abiola, A. H. (2016). The chemistry of natural product: Plant secondary metabolites. Int. J. Technol. Enhanc. Emerg. Eng. Res, 4, 1-8.
• 17. Liu, R., Pang, X., Yang, Z. (2017). Measurement of three wood materials against weathering during long natural sunlight exposure. Measurement, 102, 179-185.
• 18. Reinprecht, L., Mamoňová, M., Pánek, M., Kačík, F. (2018). The impact of natural and artificial weathering on the visual, colour and structural changes of seven tropical woods. European Journal of Wood and Wood Products, 76(1), 175-190.
• 19. Gupta, B. S., Jelle, B. P., Per Jostein, H., Rüther, P. (2011). Studies of wooden cladding materials degradation by spectroscopy. Proceedings of the Institution of Civil Engineers-Construction Materials, 164(6), 329-340.
• 20. Brischke, C., Rapp, A. O. (2008). Dose–response relationships between wood moisture content, wood temperature and fungal decay determined for 23 European field test sites. Wood Science and Technology, 42(6), 507.