机构地区:[1]中国林业科学研究院林业新技术研究所,北京100091 [2]中国林业科学研究院木材工业研究所,北京100091 [3]安徽农业大学,安徽合肥230031
出 处:《光谱学与光谱分析》2020年第1期184-188,共5页Spectroscopy and Spectral Analysis
基 金:国家“十三五”重点研发专项计划课题(2017YFD0600201)资助
摘 要:杉木(Cunninghamia lanceolata)是我国重要的速生针叶用材树种,其木材广泛应用于建筑、家具和船只等。杉木心材形成较早,心边材区别明显。快速检测新无性系心材和边材化学组分、细胞壁超微和显微构造等微观结构差异,可为了解该木材心材和边材品质性状提供重要的结构特征数据。以新培育的杉木无性系为实验材料,采用傅里叶变换红外光谱技术, X射线衍射技术,光学显微图像结合Image J图像分析技术,分别对杉木无性系洋61心材与边材的细胞壁化学组分、细胞壁纤维素结晶度及其显微构造进行了快速检测。研究结果表明,心材和边材红外光谱谱图中化学官能团的波数基本相同,即主要结构相同,其差别主要在峰强度上。心材的红外光谱谱图中酚类和醇类化合物特征峰(1 034和1 122 cm-1)及Caryl-O伸缩振动特征峰(1 264和1 232 cm-1)的吸收强度较边材的高,说明可能杉木无性系心材抽提物含量和木质素的交联程度高于边材。同时采用特征峰比值法分析了三大化学组分相对含量的变化,发现与边材相比,心材木质素相对含量增加2%~4%左右,纤维素相对含量减少约2%,半纤维素含量基本不变。通过分析X射线衍射图谱,发现杉木心材和边材的衍射图形状基本相同,不同的是边材的半高宽较心材的窄,且在2θ=22.5°处边材的峰强度高于心材,说明两者细胞壁纤维素结晶部分晶胞构造相同,但边材细胞壁纤维素结晶程度大于心材的。测算得知杉木心材相对结晶度为35.1%,边材相对结晶度为43.1%,两者在0.01水平具有显著差异。通过光学显微镜获得杉木心边材显微图像后,利用Image J图像分析技术快速检测到心材管胞腔面积比率和平均管胞面积均比边材的小,即心材细胞与边材相比具有壁厚腔小的特点。以上研究结果发现傅里叶红外光谱技术, X射线衍射技术和光学显微图像结合Image J图像分�Chinese fir(Cunninghamia lanceolata) is the most important fast-growing coniferous species in China, which is widely used in buildings, furniture and ships. Its heartwood formed earlier, and there are obvious differences between heartwood and sapwood. Rapid detection of chemical composition, cell wall ultrastructure and microstructural differences between heartwood and sapwood of new clones can provide important structural data for evaluating the quality characteristics of heartwood and sapwood. In this paper, the chemical composition of cell wall, crystallinity of cell wall cellulose and microstructure of heartwood and sapwood of Chinese fir clone Yang 61 were determined by Fourier transform infrared spectroscopy, X-ray diffraction, optical microscopy combined with Image J. The results showed that the wave numbers of chemical functional groups in FTIR spectra of heartwood and sapwood were basically the same, that is, the main structure of chemical composition was the same, and the difference between them was mainly in peak intensity. The characteristic peaks of phenols and alcohols(1 034 and 1 122 cm-1) and Caryl-O stretching vibration(1 264 and 1 232 cm-1) in infrared spectra of heartwood were higher than those in sapwood. So this showed that the content of heartwood extracts and the degree of crosslinking of lignin in Chinese fir clones heartwood are possibly higher than those of sapwood. At the same time, the change of relative content of three chemical components was analyzed by characteristic peak ratio method. It was found that the relative content of lignin in heartwood increased by 2%~4%, the relative content of cellulose decreased by 2%, and the hemicellulose content remained unchanged compared with sapwood. By analyzing the X-ray diffraction patterns, it was found that the shape of the diffraction patterns of heartwood and sapwood of Chinese fir were basically the same, but the width of the peak of sapwood was narrower than that of heartwood, and the peak intensity of sapwood was higher at 2θ=22.5°th
关 键 词:杉木 心材 边材 傅里叶红外光谱 X射线衍射 微观结构
分 类 号:S781.1[农业科学—木材科学与技术]
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