Chemical Modification of Bark Extracts to Prepare High Quality Resins.

对树皮提取物进行化学改性以制备高品质树脂。

• 批准号: 62560175
• 负责人: ABE Isao
• 金额: $ 1.22万
• 依托单位: Mie University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1988
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62560175/
• 关键词: Condensed tannin; Phenyl nucleus-exchange reaction; Phenolic pattern of tannin; Acidity function H_0; Phenolation of natural polyphenol; タンニン系; 樹脂接着剤; 樹皮抽出物; タンニン系樹脂接着剤; タンニンのフェノール化

1) Characteristics of Condensed Tannins.Chemical characteristics of wattle and quebracho tannins and the bark extracts from some species of coniferous trees were elucidated by a method combining the standard phenyl nucleus-exchange method (the NE-reaction) using BF_3 catalyst and the conventional techniques for estimating of the general aspects of the tannin.2) Phenolation and the NE-reaction of Condensed Tannin.By the treatment of condensed tannins with reagents composed of phenol and acidic catalysts, their constituent nuclei were liberated by the NE-reaction, via phenolation with phenols added as a medium in the systems. From the experimental results used bronsted acid as a catalyst, decreasing the reaction rates was observed with increasing water contents in the systems and such inhibitory effects of water were estimated to be due to the decreasing the acidity, determined as an acidity function H_0, of the system.3) Chemical Modification of Condensed Tannin by Phenol-Water Reaction … More System.The phenolation of tannin in the phenol-water-acid systems was tried to cleave of flavonoid etherocyclic rings, leading to grafting of phenols in the systems at position C-2, for the purpose of leaving out of the steric hindrance of the molecule. The experimental results show that the phenolation and the NE-reaction took place in the compound at the same time, and the phenolation rate was increased with increasing the electronegativity of phenols used as medium and the acidity of the systems.4) The Property of Tannin-Based wood Adhesive.The properties of tannin-based resins as cold- or hot-setting adhesives prepared by chemical modification with resorcinol or phenol were tested. The resorcinol-tannin adduct prepared by 1 mole of tannin and 1.05 moles of resorcinol and exhibit a reasonable cold-setting properties. On the other hand, the phenol-tannin adduct by phenolation showed suitable hot-setting abilities. However, further improved approaches are necessary to make durable and fast curing natural resins corresponded to that of the synthetic resins. Less

1)缩合单宁的特性用标准苯基核交换法和化学分析法对金合欢单宁、白坚木单宁和几种针叶树树皮提取物的化学特性进行了分析（2）酚化反应和NE-反应缩合单宁的反应：缩合单宁用酚和酸性催化剂组成的试剂处理，通过NE-反应，以酚作为介质加入到体系中，使缩合单宁的组成核释放出来。在质子酸催化下，反应速率随体系中水含量的增加而降低，水的这种抑制作用可能是由于体系的酸度（以酸度函数H_0表示）降低所致 ...更多信息 单宁在酚-水-酸体系中的酚化作用是为了使类黄酮醚环断裂，导致体系中的酚在C-2位接枝，以消除分子的空间位阻。实验结果表明，该化合物同时发生了酚化反应和NE反应，酚化反应速率随酚类介质电负性和体系酸度的增大而增大。4）单宁基木材胶粘剂的性能：用间苯二酚和苯酚对单宁基树脂进行化学改性，制备了单宁基木材胶粘剂。由1摩尔单宁和1.05摩尔间苯二酚制备的间苯二酚-单宁加合物具有合理的冷固性能。酚化单宁加合物具有较好的热定型性能。然而，需要进一步改进的方法来制造与合成树脂相对应的耐用且快速固化的天然树脂。少

项目成果

Isao,ABE: Proceedings;195th ACS National Meeting. 57 (1988)

Isao，ABE：会议记录；第 195 届 ACS 全国会议。