| 高温热处理对桃花心木化学性质的影响 |
| |
| 作者姓名： | 杨昇 付跃进 晏婷婷 陈媛 |
| |
| 作者单位： | 中国林业科学研究院木材工业研究所 |
| |
| 基金项目： | 国家重点研发计划(2017YFD0600202)。 |
| |
| 摘 要： | 热处理是木材加工行业中常用的处理手段之一,可有效提升木材尺寸稳定性及具有防生物侵蚀能力,但在一定程度上也会降低木材的力学性能。热处理导致木材材性变化的根本原因是木材组分含量及其分子结构在热量作用下发生了变化。笔者探索了不同热处理温度下(150,165,180,195和210℃)桃花心木材的化学组分变化。结果表明:经热处理后,桃花心木中的抽提物含量显著降低;处理材的p H低于未处理木材,且随处理温度升高呈下降趋势;热处理后桃花心木缓冲容量降低,随处理温度升高,呈先下降后升高趋势;桃花心木半纤维素中的木糖、甘露糖、半乳糖及葡萄糖醛酸含量随处理温度升高逐渐降低,且半纤维素大分子结构被破坏;热处理会导致桃花心木细胞壁中木质素大分子结构发生破坏,且随热处理温度升高,桃花心木中木质素单元主要连接结构(β-O-4’芳基醚键)断裂程度增加。因此,探明热处理对桃花心木化学性质的影响,将为优化桃花心木热处理工艺及合理制定热处理木材加工利用方法提供科学依据。
|
| 关 键 词： | 桃花心木 热处理 抽提物 细胞壁组分 木质素 |
Effect of high temperature heat-treatment on the chemical properties of Swietenia macrophylla |
| |
| Authors: | YANG Sheng FU Yuejin YAN Tingting CHEN Yuan |
| |
| Institution: | (Research Institute of Wood Industry,Chinese Academy of Forestry,Beijing 100091,China) |
| |
| Abstract: | Swietenia macrophylla is one of the world’s precious tree species.The heartwood of this tree is a high-quality material for the manufacture of furniture.Heat-treatment is one of the most widely used methods for wood processing.Dimensional stability and biological resistance of wood could be significantly improved after this treatment.However,the mechanical properties of wood will deteriorate to some extent.The special properties and performances of the heat-treated wood were the results of the changes of chemical compositions of the wood during heat treatment.Therefore,to adjust the wood properties through heat-treatment more efficiently,it is necessary to explore the effect of heat-treatment on the main chemical components of the wood.In this study,the Swietenia macrophylla wood was treated under different temperatures(150,165,180,195 and 210 ℃).The chemical compositions and properties of the treated Swietenia macrophylla samples were analyzed.The structural features of the lignin in the heat-treated wood were also examined using the nuclear magnetic resonance technology.Results showed that the extract contents of the heat-treated Swietenia macrophylla samples were obviously lower than that of the untreated one.However,the content of extracts increased gradually with the increase of treatment temperature.The pH values of the heat-treated wood samples were lower than that of the untreated wood.A decreasing trend was found with the treatment temperature increasing.The buffer capacity of the heat-treated wood was lower than that of the untreated one.An increase of this value was found after a decrease with the elevated treatment temperatures.The contents of xylose,mannose,galactose and glucuronic acid in the hemicelluloses of the heat-treated Swietenia macrophylla decreased with the increase of treatment temperature.The macromolecular structure of hemicelluloses was partially destroyed.Linkages between lignin structural units were damaged by the heat-treatment.The macromolecular structure of lignin in the cell wall of Swietenia macrophylla was also destroyed after the heat-treatment.The main linkages(β-O-4’ aryl ether bond) of lignin structural units decreased with the increase of treatment temperature.However,the structural units of lignin were not destroyed during this treatment process.The damage degree of heat treatment to wood cell wall structure can be judged according to the change of lignin molecular structure with the increase of treatment temperature.A well understanding of the effect of heat-treatment on the chemical properties of Swietenia macrophylla could significantly contribute to the optimization of heat-treatment process and the utilization of the treated wood. |
| |
| Keywords: | Swietenia macrophylla heat-treatment extract cell wall component lignin |
| 本文献已被 CNKI 维普 等数据库收录！ |
|
