Xinyi Chen1, Antonio Pizzi1, Hisham Essawy1,2, Emmanuel Fredon1, Christine Gerardin3, Nathanael Guigo4, Nicolas Sbirrazzuoli4. 1. LERMAB-ENSTIB, University of Lorraine, 27 rue Philippe Seguin, 88000 Epinal, France. 2. Department of Polymers and Pigments, National Research Centre, Cairo 12622, Egypt. 3. LERMAB, Faculté des Sciences, University of Lorraine, Blvd. des Aiguillettes, 54000 Nancy, France. 4. Department of Chemistry, University of the Cote d'Azur, 06103 Nice, France.
Abstract
Predominantly non-furanic commercial humins were used to prepare humin-based non-isocyanate polyurethane (NIPU) resins for wood panel adhesives. Pure humin-based NIPU resins and tannin-humin NIPU resins were prepared, the latter to upgrade the humins' performance. Species in the raw humins and species formed in the NIPU resins were identified by Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI ToF) spectrometry and Fourier Transform Infrared (FTIR). Humins, fulvic acid and derivatives, humic acid and its fragments, some lignans present and furanic oligomers present formed NIPU linkages. Thermomechanical analysis (TMA) showed that as with other biomaterials-based NIPU resins, all these resins also showed two temperature peaks of curing, the first around 130 °C and the second around 220 °C. A decrease in the Modulus of Elasticity (MOE) between the two indicated that the first curing period corresponded to linear growth of the oligomers forming a physical entanglement network. This then disentangled, and the second corresponded to the formation of a chemical cross-linked network. This second peak was more evident for the tannin-humin NIPU resins. All the laboratory particleboard made and tested either bonded with pure humins or with tannin-humin NIPU adhesives satisfied well the internal bond strength requirements of the relevant standard for interior grade panels. The tannin-humin adhesives performed clearly better than the pure humins one.
Predominantly non-furanic commercial n class="Chemical">humins were used to prepare humin-based non-isocyanate polyurethane (NIPU) resins for wood panel adhesives. Pure humin-based NIPU resins and tannin-humin NIPU resins were prepared, the latter to upgrade the humins' performance. Species in the raw humins and species formed in the NIPU resins were identified by Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI ToF) spectrometry and Fourier Transform Infrared (FTIR). Humins, fulvic acid and derivatives, humic acid and its fragments, some lignans present and furanic oligomers present formed NIPU linkages. Thermomechanical analysis (TMA) showed that as with other biomaterials-based NIPU resins, all these resins also showed two temperature peaks of curing, the first around 130 °C and the second around 220 °C. A decrease in the Modulus of Elasticity (MOE) between the two indicated that the first curing period corresponded to linear growth of the oligomers forming a physical entanglement network. This then disentangled, and the second corresponded to the formation of a chemical cross-linked network. This second peak was more evident for the tannin-humin NIPU resins. All the laboratory particleboard made and tested either bonded with pure humins or with tannin-humin NIPU adhesives satisfied well the internal bond strength requirements of the relevant standard for interior grade panels. The tannin-humin adhesives performed clearly better than the pure humins one.
Authors: Ilona van Zandvoort; Yuehu Wang; Carolus B Rasrendra; Ernst R H van Eck; Pieter C A Bruijnincx; Hero J Heeres; Bert M Weckhuysen Journal: ChemSusChem Date: 2013-07-08 Impact factor: 8.928
Authors: Anna Sangregorio; Nathanael Guigo; Luc Vincent; Ed de Jong; Nicolas Sbirrazzuoli Journal: Polymers (Basel) Date: 2022-03-03 Impact factor: 4.329