Awanda Wira Anggini^1,2, Rita Kartika Sari², Efri Mardawati^3,4, Tati Karliati⁵, Apri Heri Iswanto⁶, Muhammad Adly Rahandi Lubis^1,4,*

Journal of Renewable Materials, Vol.12, No.7, pp. 1165-1186, 2024, DOI:10.32604/jrm.2024.051854 - 21 August 2024

Abstract More than a century after its initial synthesis, urea-formaldehyde (UF) resins still have dominant applications as adhesives, paints, and coatings. However, formaldehyde in this industry produces formaldehyde emissions that are dangerous to health. Scientists have spent the last decade replacing formaldehyde and phenol with environmentally friendly substances such as glyoxal and tannin to create bio-based adhesives. This review covers recent advances in synthesizing glyoxal tannin-based resins, especially those made from sustainable raw material substitutes and changes made to synthetic processes to improve mechanical properties. The efficacy of using tannin-glyoxal adhesives in producing wood-based composites has… More > Graphic Abstract

Jaewook Lee¹, Byung-Dae Park^1,*, Qinglin Wu²

Journal of Renewable Materials, Vol.12, No.7, pp. 1187-1205, 2024, DOI:10.32604/jrm.2024.049948 - 21 August 2024

Abstract Lignin is the most abundant aromatic natural polymer, and receiving great attention in replacing various petroleum-based polymers. The aim of this study is to investigate the feasibility of technical lignin as a polyol for the synthesis of non-isocyanate polyurethane (NIPU) adhesives to substitute current polyurethane (PU) adhesives that have been synthesized with toxic isocyanate and polyols. Crude hardwood kraft lignin (C-HKL) was extracted from black liquor from a pulp mill followed by acetone fractionation to obtain acetone soluble-HKL (AS-HKL). Then, C-HKL, AS-HKL, and softwood sodium lignosulfonate (LS) were used for the synthesis of technical lignin-based… More > Graphic Abstract

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 - 11 March 2024

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… More > Graphic Abstract

Wen Gu^#, Xinyue Ding^#, Min Tang^*, Feiyan Gong^*, Shuangshuang Yuan, Jintao Duan

Journal of Renewable Materials, Vol.11, No.8, pp. 3245-3259, 2023, DOI:10.32604/jrm.2023.027461 - 26 June 2023

Abstract Biomass adhesive is conducive to decreasing the dependence of the wood adhesive industry on synthetic resin based on fossil resources and improving the market competitiveness of adhesives. It is also a critical breakthrough to realize the goal of carbon peaking and carbon neutrality in the wood industry. In this study, a full biomass wood adhesive composed of tannin and sucrose was developed and applied successfully to the preparation of plywood. The preparation technique of plywood was optimized, and the chemical structure, curing performance, crystallization property and thermal performance of the adhesive were investigated. Results showed… More >

Qianyu Zhang^1,2, Antonio Pizzi³, Hong Lei^1,2,*, Xuedong Xi^1,2,*, Ming Cao^1,2, Long Cao^1,2

Journal of Renewable Materials, Vol.11, No.3, pp. 1439-1450, 2023, DOI:10.32604/jrm.2022.023535 - 31 October 2022

Abstract Soy protein adhesives are currently a hot research topic in the wood panels industry for the abundant raw material reserves, reasonable price and outstanding environmental features. But their poor water resistance, low bonding strength and intolerance to mold are major drawbacks, so that proper modification before use is essential. Glutaraldehyde is one of the more apt cross-linking agents for soybean protein adhesives, which can effectively improve the bonding strength and water resistance of the adhesive. Equally, glutaraldehyde is also an efficient and broad-spectrum fungicide that can significantly improve the anti-fungal properties of a soy protein… More > Graphic Abstract

Claudio Del Menezzi^1,2,3, Antonio Pizzi^2,*, Siham Amirou², Xuedong Xi^4,5

Journal of Renewable Materials, Vol.11, No.2, pp. 539-553, 2023, DOI:10.32604/jrm.2022.024971 - 22 September 2022

Abstract

This article presents the first applied results of using citric acid in combinations with a melamine-urea-formaldehyde (MUF) resin for bonding wood veneers. The chemical reactions involved are shown based on a MALDI ToF analysis of the reaction of the MUF resin with citric acid. The preliminary results of the physical and mechanical properties of the LVL prepared are also presented. Veneers from Populus sp were used to manufacture 5-layer laminated veneer lumber (LVL) of small dimensions. Five combinations of the amount of citric acid, MUF spread rate and pressing parameters were tested. LVL bonded with 20%

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Saad Nader^1,2, Felipe Guzman³, Raphael Becar¹, César Segovia⁴, Cecilia Fuentealba³, Miguel Peirera³, Evelyne Mauret², Nicolas Brosse^1,*

Journal of Renewable Materials, Vol.10, No.2, pp. 263-271, 2022, DOI:10.32604/jrm.2022.017923 - 30 August 2021

Abstract The reinforcing impact of Lignocellulosic micro and nanofibrillated cellulose (L-MNFCs) obtained from Eucalyptus Globulus bark in Urea-Formaldehyde UF adhesive was tested. L-MNFCs were prepared by an environmentally friendly, low-cost process using a combination process involving steam explosion followed by refining and ultra-fine grinding. Obtained L-MNFCs showed a web-like morphology with some aggregates and lignin nanodroplets. They present a mixture of residual fibers and fine elements with a width varying between 5 nm to 20 μm, respectively. The effects of the addition of low amounts of L-MNFCs (1% wt.) on the properties of three different adhesives (Urea-Formaldehyde UF, Phenol-Formaldehyde More > Graphic Abstract

Xinyi Chen^1,2, Antonio Pizzi^1,*, Xuedong Xi^1,2, Xiaojian Zhou², Emmanuel Fredon¹, Christine Gerardin³

Journal of Renewable Materials, Vol.9, No.6, pp. 1045-1057, 2021, DOI:10.32604/jrm.2021.015066 - 11 March 2021

Abstract Soy-protein isolate (SPI) was used to prepare non-isocyanate polyurethane (NIPU) thermosetting adhesives for wood panels by reacting it with dimethyl carbonate (DMC) and hexamethylene diamine. Both linear as well as branched oligomers were obtained and identified, indicating how such oligomer structures could further cross-link to form a hardened network. Unusual structures were observed, namely carbamic acid-derived urethane linkages coupled with lactam structures. The curing of the adhesive was followed by thermomechanical analysis (TMA). It appeared to follow a two stages process: First, at a lower temperature (maximum 130°C), the growth of linear oligomers occurred, finally… More >

Jaša Saražin¹, Antonio Pizzi², Siham Amirou², Detlef Schmiedl³, Milan Šernek^1,*

Journal of Renewable Materials, Vol.9, No.5, pp. 881-907, 2021, DOI:10.32604/jrm.2021.015047 - 20 February 2021

Abstract A non-isocyanate-based polyurethane (NIPU) wood adhesive was produced from organosolv lignin, which is a bio-sourced raw material, available in large quantities and produced as a by-product of the paper industry. The formulation of this new lignin-based NIPU adhesive, which is presented, was chemically characterised by Matrix-Assisted Laser Desorption Ionization Time of Flight (MALDI ToF) mass spectrometry and by Fourier Transform Infra-Red (FTIR) spectrometry analyses. The oligomers formed were determined and showed that the three species involved in the NIPU adhesive preparation were formed by the co-reaction of the three reagents used: lignin, dimethyl carbonate, and… More >

Bengang Zhang^1,2,#, Xuedong Xi^3,#, Zhigang Wu^1,*, Hong Lei^2,*, Lifen Li¹, Meifen Tian¹

Journal of Renewable Materials, Vol.8, No.11, pp. 1429-1441, 2020, DOI:10.32604/jrm.2020.011985 - 28 September 2020

Abstract According to the preparation method commonly used for soy proteinbased adhesives, alfalfa leaf protein was used as the raw material to prepare alfalfa leaf protein-based wood adhesive. Differential scanning calorimetry analyzer (DSC), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to characterize properties of the alfalfa leaf protein-based adhesive in this paper. The results revealed the following: (1) Chemical compositions and chemical structures of the alfalfa leaf protein were basically identical with those of the soy protein, both belonging to spherical proteins with the basis and potential for protein adhesives preparation, and… More >