Elham Azadeh¹, Antonio Pizzi^1,2,*, Christine Gerardin-Charbonnier^1,*, Philippe Gerardin¹

Journal of Renewable Materials, Vol.11, No.6, pp. 2823-2848, 2023, DOI:10.32604/jrm.2023.027651

Abstract Non-isocyanate polyurethane (NIPU) foams from a commercial hydrolysable tannin extract, chestnut wood tannin extract, have been prepared to determine what chemical species and products are taking part in the reactions involved. This method is based on two main steps: the reaction with dimethyl carbonate and the formation of urethane bonds by further reaction of the carbonated tannin with a diamine-like hexamethylene diamine. The hydroxyl groups on the tannin polyphenols and on the carbohydrates intimately linked with it and part of a hydrolysable tannin are the groups involved in these reactions. The carbohydrate skeleton of the hydrolysable tannin is also able… More > Graphic Abstract

Elham Azadeh¹, Xinyi Chen², Antonio Pizzi^2,*, Christine Gérardin¹, Philip Gérardin¹, Hisham Essawy³

Journal of Renewable Materials, Vol.10, No.12, pp. 3217-3227, 2022, DOI:10.32604/jrm.2022.022740

Abstract Non-isocyanate polyurethane (NIPU) foams using a hydrolysable tannin, also vulgarly called tannic acid, namely here commercial chestnut wood tannin extract was prepared. Compression strength did not appear to depend on the foam apparent density while the formulation composition of the NIPU foams has been shown to be more determinant. These NIPU foams appeared to be self-extinguishing once the high temperature flame is removed. The ignition time gave encouraging results but for improved fire resistance the foams may need some fire-retardant addition. FTIR spectrometry showed the formation of non-isocyanate urethane linkages. Thermogravimetric analysis indicated a good thermal resistance of these foams,… More >