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    An FT-IR study of the changes in chemical composition of bamboo degraded by brown-rot fungi
    (Elsevier Sci Ltd, 2013) Dizman Tomak, Eylem; Topaloglu, Elif; Gumuskaya, Esat; Yildiz, Umit C.; Ay, Nurgul
    The objective of this study was to use FT-IR analysis to investigate the chemical composition of aged and un-aged bamboo specimens, with and without node sections, decayed by brown-rot fungi. Specimens were exposed to two brown-rot fungi, Coniophora puteana and Poria placenta, for 8 weeks after which decay was assessed by weight loss and FT-IR spectra analysis. Depending on the bamboo section examined, the aging process reduced decay resistance of specimens. Weight loss (measured as a percentage) decreased from the top to the bottom portion of bamboo culms. The presence of nodes in the specimens increased weight loss caused by P. placenta attack, and caused only a slight increase in weight loss from C puteana attack. Significant chemical changes in bamboo were observed after fungal degradation, as revealed by FT-IR analyses. Consistent with the degradation mechanism of brown-rot fungi, lignin was essentially un-degraded or modified. Both brown-rot fungi caused a sharp decrease in the carbonyl absorption area. Surprisingly, cellulose peaks of degraded specimens were nearly similar to the peaks of control specimens. Aging treatments and biodegradation affected the crystalline structure of bamboo specimens. Poria placenta degraded wood components faster and changed the crystallinity more than C puteana did, in accordance with the weight losses due to decay. (C) 2013 Elsevier Ltd. All rights reserved.
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    SURFACE PROPERTIES OF BAMBOO AND SCOTS PINE IMPREGNATED WITH BORON AND COPPER BASED WOOD PRESERVATIVES AFTER ACCELERATED WEATHERING
    (Univ Bio-Bio, 2016) Baysal, Ergun; Dizman Tomak, Eylem; Topaloglu, Elif; Pesman, Emrah
    In this study, we investigated the color, gloss and surface roughness of bamboo (Phyllostachys bambusoides) and Scots pine (Pinus sylvestris) samples impregnated with boron and copper based preservatives during accelerated weathering from 168 h to 672 h. Tanalith-E, ACQ, wolmanit-CB were used as copper-based chemicals, while a mixture of boric acid and borax (7:3; w/w) was used as the boron compound. Results showed that retention values of bamboo samples were lower than the retention values of Scots pine samples probably due to the bamboo's anatomical structure and penetration characteristic. Bamboo surfaces became rougher and darker after impregnation and accelerated weathering compared to initial surfaces. Longer accelerated weathering periods seemed to have not a considerable effect on surface roughness of bamboo samples impregnated with copper based preservatives. Gloss of impregnated Scots pine samples increased with longer accelerated weathering period while gloss of bamboo samples decreased slightly with longer accelerated weathering period. Wolmanit-CB seemed to be most effective wood preservative for hindering color change and ensuring smooth surfaces after accelerated weathering. Color changes caused by accelerated weathering tended to be greater for impregnated bamboo samples than impregnated Scots pine samples.
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    Testing the durability of copper based preservative treated bamboos in ground-contact for six years
    (Springer, 2022) Tomak, Eylem D.; Topaloglu, Elif; Ermeydan, Mahmut A.; Pesman, Emrah
    In this study, durability of bamboo samples in terms of the variability of location along culm height (top, middle and bottom) were evaluated in a ground-contact field test for six years in comparison to Scots pine and beech wood samples. Bamboo and wood samples were treated with Wolmanit-CB (CCB) and Tanalith-E (Tan-E) solutions, and then were installed in a field located in the North-West of Turkey. The decay resistance of samples was assessed by weight loss, and compared by SEM observations and FTIR analysis. Furthermore, chemical leaching from the samples was detected by ICP-OES after the test. Results showed that un-treated bamboo and wood samples had a very low durability such that weight losses were found as 64-80% for bamboo and 57-63% for wood samples. The SEM micrographs showed the characteristics decay patterns of soft-rot type I and brown-rot fungi in the parenchyma cells, vessels and fibers in vascular bundles. Fungal hyphae within the cell walls resulted in the gradual breakdown of the cell wall layers. FTIR analysis revealed the mechanism of the biodegradation, which indicates the reduction of carbohydrate content. The weight loss in CCB and Tan-E treated bamboo samples was reduced as 20-45% depending on bamboo height parts, but the wood preservatives did not ensure sufficient resistance for six years against soil degrading organisms since more than half of the chemical amount leached out from the bamboos to soil. Weight losses were well confirmed by chemical leaching rates for both CCB and Tan-E. It was observed that the lower parts of the culm were more durable, which was also in accordance with ICP-OES and SEM analysis. Copper-based preservatives seemed to be more efficient in pine and beech wood samples than bamboos since the impregnability of bamboo was much lower than that of wood.