Mechanism of polyphenolic tannin resin hardening by hexamethylenetetramine: CP–MAS 13C‐NMR
Mechanism of polyphenolic tannin resin hardening by hexamethylenetetramine: CP–MAS 13C‐NMR
复制标题
六亚甲基四胺硬化多酚单宁树脂的机理：CP-MAS 13C-NMR
DOI：
10.1002/app.1995.070561215
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发表时间：
1995
影响因子：
3
通讯作者：
P. Tekely
中科院分区：
文献类型：
--
作者：
A. Pizzi;P. Tekely
通过13 C-NMR已经表明，聚类黄酮单宁与六亚甲基四胺（六胺）的反应速率比与苯酚的反应速率高得多，同时形成苄胺和亚甲基交联以形成硬化树脂。主要是prodelphinidintype单宁似乎目前的比例高得多的苄胺桥比亚甲基桥，而在原花青素型单宁的比例，这两种类型的交联似乎是可比的。类黄酮单宁A环的亲核性越大，似乎形成的苄胺桥的比例就越大。在单宁类型相同的情况下，与六胺的反应越快，似乎形成的苄胺的比例越高。John Wiley & Sons，Inc.
Polyflavonoid tannins have been shown by 13C-NMR to react with hexamethylenetetramine (hexamine) at considerably higher rates than with phenol with the formation of both benzylamine and methylene crosslinks to form hardened resins. Predominantly prodelphinidintype tannins appear to present a much higher proportion of benzylamine bridges than of methylene bridges, while in procyanidin-type tannins the proportion of the two types of crosslinks appear to be comparable. The greater the nucleophilicity of the flavonoid tannin A-rings, the greater is the proportion of benzylamine bridges which appear to form. At parity of the type of tannins, the faster the reaction with hexamine, the higher the proportion of benzylamines which appear to form. © 1995 John Wiley & Sons, Inc.