A new 100% biosourced thermosetting plastic material, named condensed tannin–furanic thermoset is prepared and characterized in this paper. This new material is synthesized from tannin and furfuryl alcohol, both of which are inexpensive plant-derived chemicals. The co-polymerization process of these two chemicals was studied by 13C nuclear magnetic resonance (NMR) and matrix-assisted laser desorption–ionization time-of-flight (MALDI-ToF) mass spectroscopy. The 100% renewable bioresourced tannin–furanic thermosetting resin was found to have a glass transition temperature as high as 211 °C, and a 95% weight loss temperature of 244 °C and 240 °C in a nitrogen and in an air atmosphere, respectively. The char yield is as high as 52%. Moreover, this new thermoset material shows excellent mechanical properties: a Brinell hardness of 23 HBS, which is higher than commercial acrylic, polyvinyl chloride, and a little lower than that of solid polystyrene. The compressive break strength was found to be as high as 194.4 MPa, thus higher than that of filled phenolic resins, and much higher than that of solid polystyrene and of acetal resins.
