Spectrochemical characterization by FT-Raman spectroscopy of wood heat-treated at low temperatures: Japanese larch and beech
Spectrochemical characterization by FT-Raman spectroscopy of wood heat-treated at low temperatures: Japanese larch and beech
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DOI：
10.1007/s10086-004-0691-6
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发表时间：
2005-10
影响因子：
2.9
通讯作者：
S. Yamauchi;Y. Iijima;S. Doi
中科院分区：
文献类型：
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作者：
S. Yamauchi;Y. Iijima;S. Doi
以日本落叶松（Larix leptolepis）心材和日本山毛榉（Fagus crenata）边材为试材，在3种含水量条件下，恒温（50° ~ 180 ° C）加热22 h。记录热处理前后的样品的拉曼光谱，并使用差光谱法评估1000 cm-1至1800 cm-1范围内的光谱变化。对于这两种木材，在1655-1660 cm− 1处的拉曼谱带强度主要是由于木质素中的C=C和C=O基团，随着热处理温度（HTT）的升高而明显降低。光谱变化反映了热处理过程中木质素分子的缩合反应进程。此外，谱带强度的降低是相当容易的细胞壁中的水的存在下，这表明缩合是密切相关的木质素的软化。从1200-1500 cm-1波数区域的光谱变化可以认为，木材成分在较高的HTT下部分分解。
Test samples of Japanese larch (Larix leptolepis) heartwood and Japanese beech (Fagus crenata) sapwood were heated for 22 h at constant temperatures (50°–180°C) under three water content conditions. Raman spectra of the samples were recorded before and after the heat treatments, and spectral changes in the range from 1000 cm−1to 1800 cm−1were evaluated using the difference spectrum method. For both wood species, the Raman band intensity at 1655–1660 cm−1due mainly to the C=C and C=O groups in lignin clearly decreased with increasing heat-treatment temperature (HTT). The spectral change was thought to reflect the progress of condensation reactions of lignin molecules during the heat treatment. Moreover, the decrease in band intensity was considerably facilitated by the presence of water in the cell wall, suggesting that the condensation is closely related to the softening of lignin. From the spectral changes in the wavenumber region of 1200–1500 cm−1, it was considered that wood constituents are partially decomposed at the higher HTT.