Ekstraktiflerin ahşabın dış ortam dayanımına etkisinin incelenmesi
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Tarih
2024
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Yayıncı
Bursa Teknik Üniversitesi, Lisansüstü Eğitim Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Çalışmada amaç, Türkiye'de endüstriyel olarak temin edilebilen 15 farklı odun türünün (6 tür yerli, 9 tür egzotik) dış ortam koşullarında (toprak üstü kullanım yerleri) maruz kalabileceği bozundurucu faktörlere karşı dayanıklılığının doğal koşullara maruz bırakılmasıyla belirlenmesi ve bu dayanıklılık üzerinde ekstraktiflerin etkisini incelemektir. Bu amaçla doğal dayanıklılığı yüksek olan ve dış ortamda kullanım alanı bulan dut, ardıç, venge, tik, iroko, kestane, dahoma, yalancı akasya, moabi, okan, paduk, ipe, ceviz, tatajuba ve meşe odunları kullanılmıştır. Örneklerin yarısının ekstraktifleri uzaklaştırılarak ekstraktiflerin dış ortam yaşlandırmasına karşı etkinliği tespit edilmiştir. Çalışmada 2 pilot alan kullanılmıştır. Biga/Çanakkale'de deniz kenarında ve denizden uzak bir alanda 1 yıl doğal dış ortam koşullarına maruz bırakılan örneklerin renk ve yüzey pürüzlülük ölçümleri, yüzey kimyası (ATR-FTIR) ve makroskopik açıdan değerlendirilmesi 1, 3, 6, 9 ve 12 ay bounca periyodik olarak gerçekleştirilmiştir. Çalışma sonucunda, tüm örneklerde hava koşullarına maruz bırakma süresi arttıkça pürüzlülük ve renk değişimi artmıştır. Genel olarak egzotik türler, yerli türlerden daha pürüzlü yüzeyler vermiştir. Pürüzlülük değerlerine lokasyonun etkisi görülmemiştir. Yerli türlerde en pürüzlü yüzeyler meşe ve cevizde görülürken, en az pürüzlü yüzeyler ardıç ve kestanede bulunmuştur. Egzotik ağaç türleri arasında istatistiki açıdan pürüzlülük indeksi en büyük olan türler sırasıyla moabi ve okan; en düşük olanlar ise venge, iroko, paduk ve teak odunu örnekleridir. En fazla renk değişiminin yerli ağaç türü odunlarında ilk 3 ayda, ekstraktifçe zengin egzotik ağaç türü odunlarında 3-6 ay arasında meydana geldiği bulunmuştur. Koyu renkli odunlar açık renk almaya, açık renkli odunlar ise koyulaşma eğilimi sergilemiştir. Tüm ağaç türü odunlarında en fazla renk değişimi ekstrakte edilen ve denizden uzak alanda bekletilen örneklerde görülürken en düşük ekstrakte edillmemiş ve deniz kenarında bekletilen örneklerde görülmüştür. Ağaç türleri arasında paduk en fazla renk değişimine sahip olurken, moabi en az renk değişimine sahip olan odun türü olmuştur. Açık hava koşullarına maruz bırakılan türlerin yüzeylerindeki kimyasal değişimler FTIR ile 12 ay boyunca takip edilmiş ve incelenmiştir. Tüm türlerde literature uyumlu şekilde lignin bozunmasına dayalı temel kimyasal değişimler gözlenmiştir. Yerli türlerin yüzey kimyasındaki değişim ilk 1 ayda tamamlanmış olduğu, bazı egzotik türlerin yüzey kimyasındaki bozunmanın ise 3 aya kadar uzayabildiği tespit edilmiştir.
The aim of the study was to determine the resistance of 15 different industrially available wood species (6 native and 9 exotic species) to the degradation factors to which they may be exposed under outdoor conditions (above-ground use) by exposing them to natural conditions and to examine the effect of extractives on this resistance. For this purpose, mulberry, juniper, wenge, teak, iroko, chestnut, dahoma, acacia, moabi, okan, paduk, ipe, walnut, tatajuba and oak woods with high natural durability and outdoor use were used. The extractives of half of the samples were removed and the effectiveness of the extractives against outdoor aging was determined. Two pilot areas were used in the study. The color and surface roughness measurements, surface chemistry (ATR-FTIR), and macroscopic evaluation of the samples, which were exposed to natural outdoor conditions for 1 year in an area near and away from the sea in Biga/Çanakkale, were carried out periodically for 1, 3, 6, 9 and 12 months. As a result of the study, roughness, and color change increased with increasing exposure time to weathering in all samples. In general, exotic species gave rougher surfaces than native species. There was no effect of location on roughness values. In native species, the roughest surfaces were found in oak and walnut, while the least rough surfaces were found in juniper and chestnut. Among the exotic wood species, the highest roughness index was moabi and okan, and the lowest ones were wenge, iroko, padauk and teak wood samples. It was found that the maximum color change occurred in the first 3 months in native wood species woods and between 3-6 months in extractive-rich exotic wood species woods. Dark woods tended to become lighter and light woods tended to become darker. In all wood species, the highest color change was observed in extracted samples kept away from the sea, while the lowest color change was observed in unextracted samples kept near the sea. Among the wood species, padauk had the highest color change, while moabi had the least color change. The chemical changes on the surfaces of species exposed to outdoor conditions were monitored and examined for 12 months with FTIR spectroscopy. Basic chemical changes based on lignin degradation were observed in all species, consistent with the literature. It has been determined that the change in the surface chemistry of native species is completed in the first month, while the degradation on the surface chemistry of some exotic species can take up to 3 months.
The aim of the study was to determine the resistance of 15 different industrially available wood species (6 native and 9 exotic species) to the degradation factors to which they may be exposed under outdoor conditions (above-ground use) by exposing them to natural conditions and to examine the effect of extractives on this resistance. For this purpose, mulberry, juniper, wenge, teak, iroko, chestnut, dahoma, acacia, moabi, okan, paduk, ipe, walnut, tatajuba and oak woods with high natural durability and outdoor use were used. The extractives of half of the samples were removed and the effectiveness of the extractives against outdoor aging was determined. Two pilot areas were used in the study. The color and surface roughness measurements, surface chemistry (ATR-FTIR), and macroscopic evaluation of the samples, which were exposed to natural outdoor conditions for 1 year in an area near and away from the sea in Biga/Çanakkale, were carried out periodically for 1, 3, 6, 9 and 12 months. As a result of the study, roughness, and color change increased with increasing exposure time to weathering in all samples. In general, exotic species gave rougher surfaces than native species. There was no effect of location on roughness values. In native species, the roughest surfaces were found in oak and walnut, while the least rough surfaces were found in juniper and chestnut. Among the exotic wood species, the highest roughness index was moabi and okan, and the lowest ones were wenge, iroko, padauk and teak wood samples. It was found that the maximum color change occurred in the first 3 months in native wood species woods and between 3-6 months in extractive-rich exotic wood species woods. Dark woods tended to become lighter and light woods tended to become darker. In all wood species, the highest color change was observed in extracted samples kept away from the sea, while the lowest color change was observed in unextracted samples kept near the sea. Among the wood species, padauk had the highest color change, while moabi had the least color change. The chemical changes on the surfaces of species exposed to outdoor conditions were monitored and examined for 12 months with FTIR spectroscopy. Basic chemical changes based on lignin degradation were observed in all species, consistent with the literature. It has been determined that the change in the surface chemistry of native species is completed in the first month, while the degradation on the surface chemistry of some exotic species can take up to 3 months.
Açıklama
Anahtar Kelimeler
Ormancılık ve Orman Mühendisliği, Forestry and Forest Engineering, Woodworking, FTIR, Ağaç işleri
