Qianyu Zhang^1,2,#, Shi Chen^1,2,#, Long Cao^1,2, Hong Lei³, Antonio Pizzi⁴, Xuedong Xi^1,2,*, Guanben Du^1,2

Journal of Renewable Materials, Vol.12, No.2, pp. 235-244, 2024, DOI:10.32604/jrm.2023.029537

Abstract Using non-toxic, low-volatile glyoxal to completely replace formaldehyde for preparing urea-glyoxal (UG) resin adhesive is a hot research topic that could be of great interest for the wood industry. However, urea-glyoxal (UG) resins prepared by just using glyoxal instead of formaldehyde usually yields a lower degree of polymerization. This results in a poorer bonding performance and water resistance of UG resins. A good solution is to pre-react urea to preform polyurea molecules presenting already a certain degree of polymerization, and then to condense these with glyoxal to obtain a novel UG resin. Therefore, in this present work, the urea was… More > Graphic Abstract

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 >

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 >

Bowen Liu¹, Yunxia Zhou¹, Hisham Essawy², Shang Feng¹, Xuehui Li¹, Jingjing Liao¹, Xiaojian Zhou^1,3,*, Jun Zhang^1,*, Sida Xie¹

Journal of Renewable Materials, Vol.10, No.11, pp. 3009-3024, 2022, DOI:10.32604/jrm.2022.019848

Abstract This study presents easily prepared free formaldehyde bio-based foam based on a prepared thermosetting resin comprising tannin–lignin–furfuryl alcohol-glyoxal (TLFG) via mechanical stirring in presence of ether as a foaming agent. The foam was developed through a co-polycondensation reaction of glyoxal and furfuryl alcohol with condensed tannin and lignin, which is a forest-derived product. Investigation using scanning electron microscopy (SEM) showed more closed-cell structure without cracks and collapse in the TLFG foam, with a higher apparent density with respect to tannin–furanic–formaldehyde (TFF) foam. Differential scanning calorimetry (DSC), dynamic thermomechanical analysis (DTMA), and thermogravimetric analysis (TGA) investigations revealed that the curing process… More >

Abdul Awal Chowdhury Masud¹, Md. Fazlul Karim¹, M. H. M. Borhannuddin Bhuyan², Jubayer Al Mahmud³, Kamrun Nahar⁴, Masayuki Fujita⁵, Mirza Hasanuzzaman^1,*

Phyton-International Journal of Experimental Botany, Vol.90, No.2, pp. 353-372, 2021, DOI:10.32604/phyton.2021.013259

Abstract Drought is the most common form of abiotic stress that reduces plant growth and productivity. It causes plant injuries through elevated production of reactive oxygen species (ROS). Potassium (K) is a vital plant nutrient that notably ameliorates the detrimental effect of drought stress in the plant. A pot experiment was conducted at the Laboratory of Plant Stress Responses, Faculty of Agriculture, Kagawa University, Japan, under controlled environment of green house to explore the role of K in mitigating drought severity in wheat (Triticum asevitum L.) seedlings. Three days after germination, seedlings were exposed to three water regimes viz., 100, 50,… More >

Zhigang Wu^1,2,#, Jiankun Liang^3,#, Hong Lei^1,*, Bengang Zhang¹, Xuedong Xi¹, Lifen Li²

Journal of Renewable Materials, Vol.9, No.2, pp. 205-218, 2021, DOI:10.32604/jrm.2021.013655

Abstract Based on the ESI-MS and ¹³C-NMR analysis of the forms of glyoxal in acidic and alkaline solutions, the soy-based adhesive cross-linked by glyoxal was prepared in this work. The results showed that glyoxal existed in water in different forms at different pH levels. Under alkaline conditions, glyoxal transformed to glycolate through the intramolecular disproportionation reaction. Under acidic conditions, although some of glyoxal transformed to glycolate as what happened under alkaline conditions, most of glyoxal molecules existed in the form of five- or six-membered cyclic ether structure. No ethylene tetraol or free aldehyde group was actually detected under these conditions. Although… 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 >

Mahmuda Binte Monsur¹, Nasrin Akter Ivy¹, M. Moynul Haque², Mirza Hasanuzzaman³, Ayman EL Sabagh^4,5,*, Md. Motiar Rohman^6,*

Phyton-International Journal of Experimental Botany, Vol.89, No.3, pp. 497-517, 2020, DOI:10.32604/phyton.2020.09144

Abstract The research was conducted to investigate comparative oxidative damage including probable protective roles of antioxidant and glyoxalase systems in rice (Oryza sativa L.) seedlings under salinity stress. Seedlings of two rice genotypes: Pokkali (tolerant) and BRRI dhan28 (sensitive) were subjected to 8 dSm⁻¹ salinity stress for seven days in a hydroponic system. We observed significant variation between Pokkali and BRRI dhan28 in phenotypic, biochemical and molecular level under salinity stress. Carotenoid content, ion homeostasis, antioxidant enzymes, ascorbate and glutathione redox system and proline accumulation may help Pokkali to develop defense system during salinity stress. However, the activity antioxidant enzymes particularly… More >

Mohamed Ammar¹, Ramzi Khiari^2,3,4*, Mohamed Naceur Belgacem^3,4*, Elimame Elaloui¹

Journal of Renewable Materials, Vol.5, No.2, pp. 116-123, 2017, DOI:10.7569/JRM.2016.634136

Abstract The present study investigated the preparation of biomatrices from Stipa tenacissima L. and its valorization for fiberboard application. Resins were produced by extracting lignin from the Stipa tenacissima L. black liquor by soda process and combining it with glyoxal as crosslinking agent to produce lignin-glyoxal-resin (LGR). The matrix was characterized by several methods, such as FTIR and ATG/ATD, and then mixed with date palm rachis as reinforcing fibers in different proportions of 30 and 50% (w/w with respect to the matrix) to produce biodegradable composite materials. Then, their thermal and mechanical properties were determined, using differential scanning calorimetry (DSC) and… More >