抽出成分對柳杉心材光氧化之安定性評估

Stabilizing Effects of Extractives on the Photooxidation of Cryptomeria Japonica Heartwood

張資正(Tzu-Cheng Chang) ； 張惠婷(Hui-Ting Chang) ； 吳季玲(Chi-Lin Wu) ； 張上鎮(Shang-Tzen Chang)

《中華林學季刊》 42卷2期 (2009/06) Pp. 227-238

https://doi.org/10.30064/QJCF.200906.0004

摘要

抽出成分對木材光劣化的影響至今仍不甚明確，因此本研究針對未萃取及已萃取柳杉(Cryptomeria japonica)心材進行光劣化試驗，並利用傅立葉轉換紅外線光譜(FTIR)與光電子能譜(XPS)分析技術進行木材表面化學性質變化分析，探討柳杉抽出成分在木材光劣化過程中所扮演的角色。FTIR分析結果顯示，未萃取與已萃取試材經過光劣化試驗後，木質素皆會劣解產生羰基類之劣化衍生物，然而含有抽出成分之試材劣化程度較輕微。XPS粗勘分析結果顯示未萃取試材照光後之表面氧碳比(O/C)上升程度較已萃取試材高；細勘分析表面C(下标 1s)化學組成結果顯示，照光後之未萃取與已萃取試材皆會劣解，產生羰基與羧酸基等劣化衍生物，且已萃取試材之劣化衍生物主要來自木質素，而未萃取試材之劣解物則主要來自抽出成分。此外，照光之試材經過淋洗試驗後，大部分之羧酸類劣化衍生物會被移除，並以已萃取試材之移除量較多。綜合上述結果得知，在光劣化過程中，柳杉抽出成分較木質素先產生光氧化反應，因此能減緩木質素的降解。

關鍵字

柳杉 ； 抽出成分 ； 傅立葉轉換紅外線光譜 ； 木質素 ； 光氧化 ； 光電子能譜

並列摘要

The influence of extractives in the photodegradation of wood has not been fully clarified. The aim of this study was to understand the role of extractives during wood photodegradation process. FTIR and X-ray photoelectron spectroscopy (XPS) were used to analyze the variations in chemical characteristics on the wood surfaces of non-extracted and extracted Cryptomeria japonica heartwood after lightfastness test. FTIR analysis showed that lignin on the extracted wood surface degraded significantly after lightfastness test. Consequently, the contents of carbonyl and water-soluble derivatives from lignin increased markedly. However, degradation of lignin occurred to a lesser extend on the non-extracted heartwood surface. Results from XPS survey analyses revealed that non-extracted heartwood exhibited a higher O/C ratio than the extracted one. Furthermore, results from the detail analysis of C(subscript 1s) indicated that carbonyl and carboxylic derivatives increased on both specimens after lightfastness test. On extracted specimen the derivatives were mainly derived from lignin, whereas extractives were the major component for the generation of derivatives on non-extracted specimen surface. In conclusion, extractives played an essential role in retarding the photodegradation of wood and the rate of wood degradation was decreased by the presence of extractives.

並列關鍵字

Cryptomeria japonica ； Extractives ； FTIR ； Lignin ； Photooxidation ； XPS