Bengang Zhang^1,*, Antonio Pizzi^2,*, Mathieu Petrissans¹, Anelie Petrissans¹, Colin Baptiste¹

Journal of Renewable Materials, Vol.11, No.12, pp. 4097-4121, 2023, DOI:10.32604/jrm.2023.029761

Abstract Aminated tannins were prepared by reacting mimosa condensed tannin extract with ammonia yielding the substitution of many, if not all of the tannin hydroxyl groups with –NH₂ groups. A tannin-aminated tannin (ATT) particleboard coating was then prepared by reacting raw tannin extract with aminated tannin extract and thus cross-liking the two by substituting tannin’s hydroxyl groups with the –NH₂ groups on the aminated tannin to form –NH-bridges between the two. The resulting particleboard coating gave encouraging results when pressed at 180°C for 3 min. Conversely, the system in which tannin was reacted/cross-liked with urea (ATU) by a similar amination reaction… More >

M. Thébault^1,2, A. Pizzi1^3*, F.J. Santiago-Medina¹, F.M. Al-Marzouki³, S. Abdalla³

Journal of Renewable Materials, Vol.5, No.1, pp. 21-29, 2017, DOI: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… More >