Polyphenol

Magic angle spinning

Nuclear magnetic resonance spectroscopy

Food science

Proanthocyanidin

Polymer

Catechin

Organic chemistry

Diamine

Antioxidant

Flavonoid

Tannin

Chemistry

Condensation polymer

Polymers

Reaction of a condensed flavonoid tannin, namely mimosa tannin extract with a hexamethylene diamine, has been investigated. For that purpose, catechin was also used as a flavonoid model compound and treated in similar conditions. Solid-state cross-polarisation/magic-angle spinning (CP-MAS) carbon 13 nuclear magnetic resonance (13C NMR) and matrix assisted laser desorption ionisation time of flight (MALDI-ToF) mass spectroscopy studies revealed that polycondensation compounds leading to resins were obtained by the reaction of the amines with the phenolic hydroxy groups of the tannin. Simultaneously, a second reaction leading to the formation of ionic bonds between the two groups occurred. These new reactions have been shown to clearly lead to the reaction of several phenolic hydroxyl groups, and flavonoid unit oligomerisation, to form hardened resins.

Polycondensation Resins by Flavonoid Tannins Reaction with Amines