M.C. Basso^1,2, A. Pizzi^1,3,*, A. Celzard⁴

Journal of Renewable Materials, Vol.1, No.4, pp. 273-278, 2013, DOI:10.7569/JRM.2013.634125

Abstract : Simultaneously monitoring the variation of temperature, foam rising rate, internal foam pressure and dielectric polarisation, the latter being a direct measure of setting and curing of a thermosetting foam, has allowed the comparison of the dynamic variation of determinant parameters of polyurethane foams and of tannin/furanic foams of different formulation and characteristics. This monitoring provides a good description of the process and possible characteristics of the prepared foam and constitutes an invaluable tool for foam formulation. Such a comparison indicates that fundamental differences, but also similarities, exist between the foaming processes of the two classes of foam. The dynamics… More >

M.Thébault^*, A.Pizzi, E.Fredon

Journal of Renewable Materials, Vol.1, No.4, pp. 242-252, 2013, DOI:10.7569/JRM.2013.634121

Abstract Sunfl ower oil was subjected to a fl ow of compressed air containing ozone for different time periods. The addition of α-D-Glucose was used to increase the aldehyde content by reduction of the intermediate ozonides of the ozonation reaction. These new oils were analyzed by FTIR and GC-MS spectrometry, and their relative aldehyde groups content measured by the Henick method. They were then mixed with an aqueous solution of Radiata Pine tannin to form resins, subsequently analyzed by ¹³C NMR and MALDITOF mass spectrometry. Wood particleboards were then made using some of these resins as the adhesive, and their internal… More >

M.C. Lagel¹, A. Pizzi^1,2, S. Giovando³, A. Celzard⁴

Journal of Renewable Materials, Vol.2, No.3, pp. 220-229, 2014, DOI:10.7569/JRM.2014.634113

Abstract With the depletion of fossil resources, tannin extracts can be a natural alternative to some synthetic products. Hydrolysable chestnut tannin extracts have been used to partially replace phenol in PF resins for phenolic rigid foams. Phenol-formaldehyde-chestnut tannin (PFT) phenolic foams were initially made from copolymerized PFT resins of different molar ratio. The PFT foams so prepared were tested for thermal conductivity, these being slightly worse than that of pure PF foams; and for mechanical and water absorption, these two properties being better than those of pure PF foams. Indeed, PF resins represent an important part of synthetic resins. They are… More >

M.C. Lagel^1,*, A. Pizzi^1,2, S. Giovando³

Journal of Renewable Materials, Vol.2, No.3, pp. 207-219, 2014, DOI:10.7569/JRM.2014.634111

Abstract Natural hydrolysable chestnut tannin extracts used to partially substitute phenol in Phenol-Formaldehyde (PF) resins for phenolic rigid foams were analysed by matrix-assisted desorption ionization time of fl ight (MALDI-TOF) mass spectrometry. PF only, chestnut only and PF-chestnut copolymerised oligomer types and distribution were determined. MALDI-TOF analyses of a PF control resin (with the same molar ratio) and of chestnut tannin extracts were performed in order to identify the peaks of molecular weights corresponding to copolymers of chestnut tannins with phenol and formaldehyde. More >

A. Sauget^1,*, X. Zhou¹, A. Pizzi^1,2

Journal of Renewable Materials, Vol.2, No.3, pp. 186-200, 2014, DOI:10.7569/JRM.2013.634138

Abstract Glyoxal and glutaraldehyde are two viable alternatives to formaldehyde for the preparation of tanninresorcinol-aldehyde adhesive but lead to less resistant glue joint. Tannin-resorcinol-glyoxal (TRG1) and tannin-resorcinol-glutaraldehyde (TRG2) resins have been prepared and analyzed by matrix-assisted laser desorption/ionization time of fl ight (MALDI-ToF) spectrometry to understand the chemical process behind the pre-curing of these resins and possibly the causes of this lower resistance. The analysis showed that TRG resins are not a simple mix of resorcinol-aldehydes oligomers and fl avonoids, but a much more complex combination of various species including tannin-aldehydes and tannin-resorcinol oligomers. More >

M.C. Basso^1,2, S. Giovando³, A. Pizzi^2,4,*, M.C. Lagel^2,3, A. Celzard⁵

Journal of Renewable Materials, Vol.2, No.3, pp. 182-185, 2014, DOI:10.7569/JRM.2013.634137

Abstract Condensed fl avonoid tannin foams were obtained under alkaline conditions. This entailed the elimination of furfuryl alcohol from these formulations, as under alkaline conditions, foam preparation could not rely on the heat generated by the self-condensation of furfuryl alcohol, which occurs only under strongly acidic conditions. The approach used to formulate the alkaline foam was: (i) the total elimination of furfuryl alcohol from the formulation, (ii) coupled with the use of an aldehyde hardener different from formaldehyde (for environmental reasons) and (iii) the application of moderate heat to allow foaming. These were not tannin/ furanic foams as their acid-curing counterparts,… More >

A. Sauget^1,*, X. Zhou¹, A. Pizzi^1,2

Journal of Renewable Materials, Vol.2, No.3, pp. 173-181, 2014, DOI:10.7569/JRM.2013.634128

Abstract Tannin-resorcinol-formaldehyde (TRF) resin shows a good compatibility with natural fl ax fi bers and yields composite materials of good mechanical properties when using paraformaldehyde as a hardener. Different formulations, curing parameters and processes such as high-temperature curing in press or spray-drying have been explored in order to adapt this resin to composite manufacturing and to improve the properties of this new material. Additional testing has been performed on the TRF resin by thermomechanical analysis to observe its reactivity at different pH and with the use of different hardeners. More >

Houda Saad^1,2,*, Antonio Pizzi^3,4, Bertrand Charrier², Naceur Ayed¹, Karsten Rode⁵, Fatima Charrier - El Bouhtoury²

Journal of Renewable Materials, Vol.3, No.1, pp. 34-43, 2015, DOI:10.7569/JRM.2014.634130

Abstract The possible use of Tunisian pomegranate tannins in wood adhesive formulation was studied for the fi rst time. Colorimetric tests, Fourier transformed infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and matrix-assisted laser desorption/ionization time-of-fl ight (MALDI-TOF) mass spectrometry were used to examine pomegranate tannins. Analysis showed that pomegranate peels are rich in hydrolyzable tannins. The Stiasny number tests showed the low reactivity of pomegranate tannin extract to formaldehyde and thus the diffi culty of using it in wood adhesive formulation. Thermomechanical analysis (TMA) and strength analysis of pomegranate tannin/hexamine-based resin showed weak bonding properties. More >

X. Li¹, A. Pizzi^1,2,*, X. Zhou^3,*, V. Fierro⁴, A. Celzard⁴

Journal of Renewable Materials, Vol.3, No.2, pp. 142-150, 2015, DOI:10.7569/JRM.2014.634117

Abstract Tannin/furanic foams, typically 95% composed of materials of natural origin such as prorobinetinidin/ profi setinidin tannins and furfuryl alcohol, are potential alternatives to oil-based synthetic foams such as phenol-formaldehyde, and polyurethane foams. This article describes the development of second generation tannin/furanic foams, which are not only formaldehyde free, but also use nonvolatile, nontoxic aldehydes. Both glyoxal and glutaraldehyde were tried to substitute formaldehyde in tannin/furanic foams. The physical properties of these new foams are described and discussed. It was found that glutaraldehyde can totally substitute formaldehyde during tannin/furanic foam preparation, but that glyoxal cannot. The optimized proportion to prepare such… More >

Antonio Pizzi^*

Journal of Renewable Materials, Vol.11, No.1, pp. 1-25, 2023, DOI:10.32604/jrm.2022.023314

Abstract Soy flour (SF), soy protein and soy protein isolates (SPI) have been the focus of increasing research on their application as new materials for a variety of applications, mainly for wood adhesives and other resins. Tannins too have been the focus of increasing research for similar applications. While both materials are classed as non-toxic and have achieved interesting results the majority of the numerous and rather inventive approaches have still relied on some sort of hardeners or cross-linkers to bring either of them or even their combination to achieve acceptable results. The paper after a presentation of the two materials… More >