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 >

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 >

Haizhu Wu^1,#, Jinxing Li^1,#, Shouhu Bao¹, Fuxian Yang¹, Jun Zhang¹, Hisham Essawy^2,*, Guanben Du¹, Xiaojian Zhou^1,*

Journal of Renewable Materials, Vol.10, No.8, pp. 2029-2039, 2022, DOI:10.32604/jrm.2022.019834

Abstract A cellular material in the form of 3-layered sandwich structure material was prepared via sole use of mechanical stirring without any use of a foaming agent, while Tween-80 was employed as a foam stabilizer via a developed in-situ mold casting. The resulting structure displayed a good appearance with no visual defects. The 3-layered composition of the sandwish structure, “nonporous resin layer-porous foam layer-nonporous resin layer”, was examined in terms of the microstructure, density & density distribution, pulverization ratio, mechanical strength, insulation and flame retardant performance. It was indicated from the results that the bonding between the resin layer and foam… More > Graphic Abstract

Achille Gnassiri Wedaïna^1,2, Antonio Pizzi², Wolfgang Nzie¹, Raidandi Danwe³, Noel Konaï^4,*, Siham Amirou², Cesar Segovia⁵, Raphaël Kueny⁵

Journal of Renewable Materials, Vol.9, No.3, pp. 477-493, 2021, DOI:10.32604/jrm.2021.012782

Abstract The Piptadeniastrum Africanum bark tannin extract was characterized using MALDI TOF, ATR-FT MIR. It was used in the development of a resin with Vachellia nilotica extract as a biohardener. This tannin is consisting of Catechin, Quercetin, Chalcone, Gallocatechin, Epigallocatechin gallate, Epicatechin gallate. The gel time of the resin at natural pH (pH = 5.4) is 660 s and its MOE obtained by thermomechanical analysis is 3909 MPa. The tenacity of Urena lobata fibers were tested, woven into unidirectional mats (UD), and used as reinforcement in the development of biocomposite. The fibers tenacity at 20, 30 and 50 mm lengths are… More >

Jinxing Li¹, Jun Zhang^1,*, Yunxia Zhou¹, Zhaoling Zhou¹, Hisham Essawy², Xiaojian Zhou^1,*, Guanben Du¹

Journal of Renewable Materials, Vol.8, No.9, pp. 1019-1032, 2020, DOI:10.32604/jrm.2020.012374

Abstract Simple bio-based abrasive grinding wheel based on thermosetting resin matrix was developed starting with condensed tannin and furfuryl alcohol, which are mainly derived from forest and agricultural products like tree barks, wheat and crops. Fourier transform infrared spectra (FTIR) signified the acidic conditions are quiet efficient for the reaction of furfuryl alcohol, urea and glyoxal all together and the -CH₂-NH- and -CH₂-O-CH(OH)- groups are predominating in cross-linking of the tannin-furfuryl alcohol-urea-glyoxal (TFUG) resin. The strengthening contribution of the tannin was also confirmed by the preservation of its distinct crystallinity using X-ray diffraction (XRD). Differential scanning calorimetry (DSC) and thermogravimetric analysis… More >