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

Zeinab Osman^1,2,3,*, Antonio Pizzi^2,*, Bertrand Charrier³

Journal of Renewable Materials, Vol.12, No.7, pp. 1291-1310, 2024, DOI:10.32604/jrm.2024.051619 - 21 August 2024

Abstract Tannin was extracted from different subspecies of Acacia nilotica, Acacia nilotica nilotica (Ann), Acacia nilotica tomentosa (Ant) and Acacia nilotica adansonii (Ana). The aim was to elucidate their structure and evaluate their reactivity as bioadhesives in the wood industry. The extracts were prepared by hot water extraction (90°C temperature). Their gel time with paraformaldehyde was used at first to compare their reactivity. The tannin contents and the percentage of total polyphenolic materials in different solutions of the extracts spray dried powder were determined by the hide powder method. Concentrated solutions (47%) were tested by both MALDI ToF, CNMR.… 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

Rafidah Md Salim^1,2,*, Jahimin Asik², Mohd Sani Sarjadi²

Journal of Renewable Materials, Vol.12, No.4, pp. 737-769, 2024, DOI:10.32604/jrm.2024.045695 - 12 June 2024

Abstract Lignin extraction from bark can maximize the utilization of biomass waste, offer cost-effectiveness, and promote environmental friendliness when employed as an adhesive material in bark particleboard production. Particles of fine (0.2 to 1.0 mm), medium (1.0 to 2.5 mm), and coarse (2.5 to 12.0 mm) sizes, derived from the bark of Leucaena leucocephala, were hot-pressed using a heating plate at 175°C for 7 min to create single-layer particleboards measuring 320 mm × 320 mm × 10 mm, targeting a density of 700 kg/m. Subsequently, the samples were trimmed and conditioned at 20°C and 65% relative humidity.… 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

Antonio Pizzi^*

Journal of Renewable Materials, Vol.11, No.9, pp. 3403-3415, 2023, DOI:10.32604/jrm.2023.030930 - 20 July 2023

Abstract This brief article reviews a very particular and quite narrow field, namely what has been done and what is needed to know for tannin adhesives for wood panels to succeed industrially. The present fashionable focus on bioadhesives has led to producing chemical adhesive formulations and approaches for tannin adhesives as a subject of academic publications. These, as good and original they might be, are and will still remain a rather empty academic exercise if not put to the test of real industrial trials and industrial use. They will remain so without the “little” secrets and… More >

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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Weixing Zhang, Chunxia He^*

Journal of Renewable Materials, Vol.10, No.12, pp. 3263-3283, 2022, DOI:10.32604/jrm.2022.020516 - 14 July 2022

Abstract With the exponential growth of the computing power, machine learning techniques have been successfully used in various applications. This paper intended to predict and optimize the shear strength of single lap cassava starchbased adhesive joints for comparison with the application of artificial intelligence (AI) methods. The shear strength was firstly determined by the experiment with three independent experimental variables (starch content, NaOH concentration and reaction temperature). The analysis of range (ANORA) and analysis of variance (ANOVA) were applied to investigate the optimal combination and the significance of each factor for the shear strength based on… More >