[article]
Titre : |
Mechanism of vegetable tannin-aldehyde combination tannage |
Type de document : |
texte imprimé |
Auteurs : |
Zhongbing Lu, Auteur ; Bi Shi, Auteur ; Yi Tao, Auteur ; Wenhua Zhang, Auteur ; Xuepin Liao, Auteur |
Année de publication : |
2005 |
Article en page(s) : |
p. 432-437 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Index. décimale : |
675.2 Préparation du cuir naturel. Tannage |
Résumé : |
Using (+)-Catechin and (+)-gallocatechin as models for condensed vegetable tannins, the reaction mechanism between the flavonoid ring structure and aldehyde was elucidated based on the density functional theory (DFT) calculation. The results show that A-ring of the flavonoid structure is the nucleophilic center, according to the atomic charges and the distribution of highest occupied molecular orbital (HOMO), which implies that A-ring is more reactive to aldehydes. As to (+)-catechin, C-6 and C-8 positions are of equal reactivity to aldehydes, according to the energy transformations in the reaction. C-8 of (+)-gallocatechin is more reactive than C-6 in the same molecule. The difference of B-rings between (+)-catechin and (+)-gallocatechin influences the distribution of HOMO in molecules and consequently leads to difference of relative reactivity between C-6 and C-8-positions in flavonoid structures, in agreement with the NMR observations. The difference of HOMO distributions of (+)-catechin and (+)-gallocatechin imply that gallocatechin-based tannins, such as mimosa tannins, have higher reactivity to aldehyde, and are more suitable for tannin-aldehyde combination tannage. |
En ligne : |
https://drive.google.com/file/d/1cHECt3xPcyyVPCDBd_-Ovu9K6dDC2bPD/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4052 |
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. C, N° 11 (11/2005) . - p. 432-437
[article]
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