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Establishment of Method for Measuring Molecular Orientation in Wood by Fluorescence Method and Its Application

荧光法测定木材分子取向方法的建立及其应用

基本信息

批准号：
61560186
负责人：
FUSHITANI Masami
金额：
$ 1.28万
依托单位：
Tokyo University of Agriculture and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

1. We investigated the method for measuring the molecular orientation of lignin by the use of the fluorescence emitted from wood itself. The corrected ratio of each polarized component of fluorescence intensity to that with the polarizer and the analyzer aligned parallel to the longitudinal direction was obtained by extrapolating a straight line of sample thickness vs. its ratio to zero. The degree of molecular orientation calculated from these ratios ranged from 0.003 to 0.094.2. The uncorrected value of degree of molecular orientation of hardwood native to Japan which was obtained from the orientation of fluorescent molecules introduced into wood was hardly varied by a highly acetylating treatment, whereas that of softwood and lauan was markedly decreased by it. This marked increase resulted from the increase in fluorescence intensity of lignin itself due to the highly acetylating treatment. The introduction of fluorescent molecules into wood was inhibited by the treatment, but it is unclear whether wood components dyed with the fluorescent molecules change or not.3. The distribution of fluorescence intensity in the cell wall of wood was observed with a fluorescence microscope. The fluorescence emitted from wood itself near the compound middle lamella and outer layer of secondary wall was strong, and the fluorescence intensity in the middle lamella was hardly increased by the introduction of fluorescent molecules into wood. The acetylated woo had a similar tendency.4. The relationship between structure factors and softening of wood due to heat and water was investigated. The degree of molecular orientation in the amorphous area had the greatest effect on the specific Young's modulus under every condition. Woods with small values of the degree of crystallinity and Klason lignin content have small values of specific Young's modulus and large values of breaking strain when they are softened with heat and water.

1.本文研究了利用木材自身发出的荧光来测定木质素分子取向的方法。荧光强度的每个偏振分量与偏振器和分析器平行于纵向方向对齐的情况下的荧光强度的每个偏振分量的校正比率通过将样品厚度的直线与其比率外推至零来获得。从这些比率计算的分子取向度的范围从0.003至0.094.2。由引入木材的荧光分子取向得到的日本硬木的分子取向度的未校正值几乎不受高度乙酰化处理的影响，而软木和柳杉的分子取向度的未校正值则明显降低，这种显著增加是由于高度乙酰化处理使木质素本身的荧光强度增加所致。处理抑制了荧光分子向木材中的引入，但不清楚荧光分子染色的木材组分是否发生变化.用荧光显微镜观察了木材细胞壁荧光强度的分布。在次生壁复合中层和外层附近，木材自身发出的荧光较强，而荧光分子的引入几乎不增加中层的荧光强度。乙酰化羊毛也有类似的趋势.研究了木材结构因素与木材热软化和水软化的关系。非晶区的分子取向度对每种条件下的比杨氏模量影响最大。木材的结晶度和Klason木质素含量的值小，具有小的值的特定的杨氏模量和大的值的断裂应变时，它们被软化与热和水。