Research on crystal structure of wood cellulose

木质纤维素晶体结构的研究

• 批准号: 61560183
• 负责人: OKANO Takeshi
• 金额: $ 1.09万
• 依托单位: The University of Tokyo
• 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
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61560183/
• 关键词: Wood cellulose; Cellulose crystal; X-ray diffraction; Analysis of crystal structure; Packing analysis; 酸加水分解; セルロース結晶; 結晶構造解折

We have predicted that lattice parameters and X-ray diffraction intensity of cellulose crystals vary due to the variety of its origins. To confirm the results obtained from previous study, cellulose samples from two sftwoods of akamatsu and karamatsu, and tow hardwoods of keyaki and redmeranti, which were thought to be the most important cellulose origin, were subjected to delignification and/or acid hydrolysis treatment and their structural modification was analysed. In adition, we refined the crystal structure of wood cellulose by the computer program of PS79, developed by A.sarko and P.Zugenmaier. Firstly, concerning the predicted variety of crystal structure of cellulose in relation to its origin, we have thoroughly investigate the effects of acid-hydrolysis, because any change caused to crystal structure with delignification treatment. The results obtained from acid hydrolysis by 2.4N boiling HCl aq. for 0 to 16hrs were followings.1. Samples without any treatment gave a clear diff … More erence in the monoclinic angle ; of softwood was 1.5 degree larger than that of hardwood. Since relative ratio of X-ray diffraction intensity R was smaller in the case of softwood and R smaller in hardwood, the structural difference of these two groups should result.2. Accompanying the progress of acid-hydrolysis, (1)while of softwood decreased about 1.1-1.4 degree, that of hardwood decreased 0.5 deg. or sometime increased 0.1 deg. Thus, the difference in was reduced. (2)Any change in fiber repeat was noticeable. (3)In both case, softwood and hardwood, R value decreased and R increased. The rate of decreasing and increasing value was not equal between two groups so that the difference in R and R value was minimized. These lives of investigation suggest that the predicted difference between softwood and hardwood is caused by amorphous cellulose and/or hemicellulose, which can be removed by hydrolysis.3. Regard to structural model of cellulose, the refinement analysis suggests that cellulose crystal prefer, (1)tg conformation of O6 position, (2) cellulose chains at the corner and the center of the unit cell rotate each other around their molecular axis about 43-45 degree in akamatsu, karamatsu and red meranti, and about 48-49 degree in keyaki. Longitudinal shift of these chains was about 2.4 A, being independent form the species. Less

我们预测，晶格参数和X射线衍射强度的纤维素晶体的变化，由于其来源的多样性。为了证实从以前的研究中得到的结果，从赤松和Karamatsu两种sftwood，和两个硬木的keyaki和redmeranti，这被认为是最重要的纤维素来源，纤维素样品进行脱木素和/或酸水解处理，并分析其结构变化。此外，我们还利用A.sarko和P. Zugenmaier开发的PS 79计算机程序对木材纤维素的晶体结构进行了精细化。首先，考虑到纤维素晶体结构的预测变化与其来源的关系，我们已经彻底研究了酸水解的影响，因为任何变化都会导致脱木质素处理的晶体结构。用2.4N沸腾的HCl水溶液酸水解得到的结果。0 ~ 16小时的处理结果如下：1.未经任何处理的样本与对照组相比， ...更多信息 针叶材的单斜角比阔叶材大1.5 °。由于X射线衍射强度的相对比值R在软木中较小，而在硬木中较小，这两组的结构差异应该是由此产生的.随着酸解过程的进行，（1）针叶材的酸解度下降1.1-1.4度，阔叶材的酸解度下降0.5度;或者有时增加0.1 °。因此，差异缩小了。（2）纤维重复数变化明显。(3)In无论是针叶木还是阔叶木，R值都呈下降趋势，R值呈上升趋势。两组之间的下降和增加值的比率不相等，从而使R和R值的差异最小化。这些研究表明，软木和硬木之间的预测差异是由无定形纤维素和/或半纤维素引起的，它们可以通过水解除去。对于纤维素的结构模型，精修分析表明：（1）O 6位的tg构象;（2）赤松、Karamatsu和红毛桉的角部和中心的纤维素链绕分子轴旋转约43-45度，而键烧的角部和中心的纤维素链绕分子轴旋转约48-49度。这些链的纵向位移约为2.4A，与物种无关。少

项目成果

OKANO Takeshi: BIOPOLYMERS. 27. (1988)

冈野武：生物聚合物。

OKANO,Takeshi: BIOPOLYMERS. 28. (1989)

冈野武：生物聚合物。