Zeinab Osman^1,2,3,*, Antonio Pizzi^2,*, Bertrand Charrier³

Journal of Renewable Materials, Vol.12, No.7, pp. 1291-1310, 2024, DOI:10.32604/jrm.2024.051619 - 21 August 2024

Abstract Tannin was extracted from different subspecies of Acacia nilotica, Acacia nilotica nilotica (Ann), Acacia nilotica tomentosa (Ant) and Acacia nilotica adansonii (Ana). The aim was to elucidate their structure and evaluate their reactivity as bioadhesives in the wood industry. The extracts were prepared by hot water extraction (90°C temperature). Their gel time with paraformaldehyde was used at first to compare their reactivity. The tannin contents and the percentage of total polyphenolic materials in different solutions of the extracts spray dried powder were determined by the hide powder method. Concentrated solutions (47%) were tested by both MALDI ToF, CNMR.… More > Graphic Abstract

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 More >