Open Access

ARTICLE

Isocyanate-Free Polyurethanes by Coreaction of Condensed Tannins with Aminated Tannins

by

1 Laboratory of Studies and Research on Wood Material (LERMAB), University of Lorraine, 88000 Epinal, France
2 Kompetenzzentrum Holz (WoodKPlus), 9300 Sankt Veit-an-der-Glan, Austria
3 Department of Physics, King Abdulaziz University, Jeddah, Saudi Arabia

*Corresponding author:

Journal of Renewable Materials 2017, 5(1), 21-29. https://doi.org/10.7569/JRM.2016.634116

Abstract

Isocyanate-free polyurethane resins biosourced to a very high percentage level were prepared by the reaction of aminated mimosa tannin extract with commercial mimosa tannin extract prereacted with dimethyl carbonate. The reaction took place with ease at ambient temperature. Indications were that the polyurethanes obtained formed a hard film when cured at a temperature higher than 100 °C. Furthermore, the carbohydrate fraction of the tannin extract also appeared to be carbonated and reacted to generate isocyanate-free polyurethane linkages with the aminated tannins. This indicated that not only the polyphenolic fraction of the tannin extract, but also its other major component, can be used to prepare polyurethane resins. Flavonoid monomers and oligomers carbonated at different levels, both unreacted and urethane-linked to aminated flavonoid monomers and oligomers, were identified by FTIR and MALDI-TOF spectrometry.

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Keywords

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