Functionalized green tea tannins as phenolic prepolymers for bio-based epoxy resins

Phenolic extract from the green tea leaves was used for the production of thermoset epoxy resins. The commercial green tea extract (GTE) was functionalized by the reaction with epichlorohydrin in the presence of phase transfer catalyst. The glycidyl ether derivative of the green tea extract (GEGTE) obtained with a good yield was cured in epoxy polymer with isophorone diamine (IPD) and the resulting network was compared to catechin-IPD and diglycidyl ether of bisphenol A (DGEBA-IPD) systems. The thermal and mechanical analyses of this bio-based epoxy polymer showed its high reactivity associated with a high crosslinking density (T-g: 140-190 degrees C), a high thermal resistance and interesting mechanical properties. (C) 2014 Elsevier B.V. All rights reserved.