Antonio Pizzi^*

Journal of Renewable Materials, Vol.14, No.7, 2026, DOI:10.32604/jrm.2026.02026-0056 - 28 July 2026

Abstract Cross Polarization Magic Angle Spinning Carbon 13 Nuclear Magnetic Resonance (CP-MAS ¹³C NMR) analysis of commercial procyanidin (pine bark) and delphinidin (pecan nut membranes) condensed flavonoid tannin extracts reacted with hexamethylenetetramine (hexamine) have shown that due to the highly reactive imino-amino methylene species formed before its degradation reaches the generation of formaldehyde, benzylamine bridges between the flavonoid units are formed. This study shows that tannin-based biobenzoxazines are also generated at the same time, with both benzylamines and benzoxazines bridges being in more marked proportions, the more reactive the tannin reacted with hexamethylenetetramine is. This is not More > Graphic Abstract

Khanh Nguyen-Trong^1,*, Tan Nguyen-Thi-Thanh²

CMC-Computers, Materials & Continua, Vol.88, No.3, 2026, DOI:10.32604/cmc.2026.083365 - 23 July 2026

Abstract Automated wood surface defect detection is difficult to evaluate reliably because defects are often small, low-contrast, and visually confounded by natural wood texture, while reported performance can vary substantially with benchmark design and domain shift. To address this issue, we conduct a comparative study across three practically relevant settings: a curated seven-class benchmark, a broader in-domain seven-class protocol derived from the same source dataset, and supervised adaptation to a low-resource Vietnamese target domain. We compare lightweight two-stage detectors based on Faster Region-based Convolutional Neural Network (Faster R-CNN) with MobileNetV3-FPN against a compact You Only Look… More >

Minyan Zhan¹, Wei Yang^2,3, Minghao Wu^4,*, Hsin-Yi Wang⁵, Yu-Hsien Ho⁵

Structural Durability & Health Monitoring, Vol.20, No.3, 2026, DOI:10.32604/sdhm.2026.077926 - 18 May 2026

Abstract The inclination of wooden columns is a key indicator for evaluating the structural safety of traditional timber buildings in China. However, accurate measurement is challenging because these columns typically exhibit natural tapering, with diameters decreasing from the base to the top, and surface irregularities such as artificial cuts, cracks, and knots. Both the intrinsic geometric characteristics and surface defects reduce the precision of coordinate acquisition and the reliability of inclination estimation. To overcome these limitations, this study proposes a novel inclination measurement method for wooden columns in traditional timber buildings based on multi-section measurement and… More >

Hamed Younesi-Kordkheili^1,*, Antonio Pizzi^2,*, Ghorban Niyatzadeh³

Journal of Renewable Materials, Vol.14, No.4, 2026, DOI:10.32604/jrm.2026.02026-0013 - 24 April 2026

Abstract In this research, an effective method has been developed to bond wood panel adhesives of good performance using biosourced lignin and chitosan as the two main raw materials. Lignin was thus modified by a deep eutectic solvent (DES) and maleic anhydride (MA), respectively. Then DES/MA modified lignin was reacted with glyoxal to obtain a new environmentally friendly lignin-glyoxal (LG) resin. Next, chitosan was added as a bio-crosslinker to the synthesised LG resin. Finally, the performance of the resulting adhesives was evaluated by bonding plywood panels with them. Fourier Transform Infra Red (FTIR) analysis was used… More > Graphic Abstract

Muhammad Ilham Aulia¹, Alifah Syahfitri¹, Imam Busyra Abdillah¹, Abdus Syukur¹, Dede Hermawan^1,*, Rita Kartika Sari¹, Mahdi Mubarok¹, Muhammad Adly Rahandi Lubis², Sukma Surya Kusumah², Sarah Augustina², Jajang Sutiawan^2,*

Journal of Renewable Materials, Vol.14, No.4, 2026, DOI:10.32604/jrm.2025.02025-0160 - 24 April 2026

Abstract Citric acid adhesive is an alternative to formaldehyde-based adhesives that are more environmentally friendly because they are non-toxic and made from natural ingredients. This study aims to determine the effect of variations in citric acid adhesive concentrations on the physical and mechanical properties of jabon plywood. This study used citric acid adhesive with variations in citric acid (CA) concentrations of 59%, 69%, and 79%. Physical property tests include density, moisture content (MC), water absorption (WA), thickness expansion (TS), and delamination, while mechanical tests include modulus of rupture (MOR), modulus of elasticity (MOE), and shear stress… More >

Belén Rovira^1,*, Aude Chabrelie¹, Sauro Bianchi², Frédéric Pichelin¹

Journal of Renewable Materials, Vol.14, No.3, 2026, DOI:10.32604/jrm.2025.02025-0173 - 25 March 2026

Abstract The construction sector is facing significant challenges in transitioning to a defossilised system. While wood-based products have considerable potential, reliance on adhesives derived from fossil fuels poses significant sustainability concerns. Tannin-based adhesives present a compelling bio-based alternative, offering advantageous bonding properties with the potential to reduce toxicity, minimise fossil resource use, and enhance end-of-life scenarios. Despite extensive research demonstrating the technical potential of tannin-based adhesives, industrial adoption remains limited—partly due to the paucity of studies addressing their environmental impacts. The present study investigates the use of tannin-based adhesives in the production of interior-grade plywood, employing… More >

Hapidh Alaudin Syalsabil¹, Imam Wahyudi^2,*, Deazy Rachmi Trisatya^1,3, Sarah Augustina^3,*, Sari Delviana Marbun⁴

Journal of Renewable Materials, Vol.14, No.3, 2026, DOI:10.32604/jrm.2026.02025-0161 - 25 March 2026

Abstract The increasing need for efficient, sustainable, and environmentally friendly adsorbent materials has driven interest in bio-based alternatives. Conventional silica-based adsorbents, while effective, are often brittle and energy-intensive to produce. In contrast, wood offers a renewable and low-energy option with natural porosity suitable for adsorption. This study investigated the fabrication of wood sponge from tropical balsa (Ochroma bicolor) and pulai (Alstonia scholaris) wood through a dual-stage delignification process as a novel bio-based adsorbent. The process involved alkaline treatment using sodium sulfite (Na₂SO₃) and sodium hydroxide (NaOH) at 100°C for 8, 9, and 10 h, followed by bleaching process using… More > Graphic Abstract

Awanda Wira Anggini^1,2, Rita Kartika Sari^1,*, Dede Hermawan¹, Muhammad Iqbal Maulana², Wahyu Hidayat³, Bora Jeong⁴, Muhammad Adly Rahandi Lubis^2,5,*

Journal of Renewable Materials, Vol.14, No.3, 2026, DOI:10.32604/jrm.2025.02025-0114 - 25 March 2026

Abstract Recent advancements in developing tannin-based non-isocyanate polyurethane (NIPU) resins have unlocked new possibilities for sustainable and eco-friendly wood adhesives. Unlike conventional polyurethane, NIPUs eliminate hazardous isocyanates, offering safer alternatives for industrial applications. Tannin, a naturally occurring polyphenolic compound, plays a pivotal role in enhancing these resins’ fire-resistance and super-hydrophobic properties. This review highlights key developments in synthesizing tannin-based NIPU, focusing on various polymerization techniques such as polyaddition, polycondensation, ring-opening polymerization, and rearrangement. These strategies contribute to improved mechanical strength, thermal stability, and resistance to water absorption. Recent studies demonstrate that tannin-based NIPU adhesives meet or… More > Graphic Abstract

Hikaru Kobori¹, Emilia-Adela Manea Salca^2,*, Tetsuya Inagaki³, Shigehiko Suzuki⁴, Sahriyanti Saad⁵, Aujchariya Chotikhun⁶

Journal of Renewable Materials, Vol.14, No.2, 2026, DOI:10.32604/jrm.2025.02025-0152 - 25 February 2026

Abstract Heat treatment is applied to wood to improve various properties of the material. The present study focuses on the colour changes of wood veneer samples due to heat treatment. Native wood species from Japan and Europe, such as Japanese oak (Quercus mongolica var. crispula), field maple (Acer campestre) and Scots pine (Pinus sylvestris) were used in the experiments. A laboratory-type oven was used to apply the heat at a temperature of 190°C, in the presence of oxygen, for different periods, gradually increasing from 5 to 40 min. The CIELab system (a colour space defined by the International Commission… More >

Faiz Rahman, Rafidah Md Salim^*, Janshah Mohktar

Journal of Renewable Materials, Vol.14, No.2, 2026, DOI:10.32604/jrm.2026.02025-0066 - 25 February 2026

Abstract The growing demand for renewable energy has increased the use of wood pellets as a clean and efficient biomass fuel. This study aims to evaluate the physical properties of wood pellets produced from Acacia hybrid (AC) veneer waste and Pine wood (PW) waste mixed with varying ratios. The objectives are to investigate the effect of different blend ratios of Acacia hybrid veneer waste and pine wood waste on the physical properties, specifically moisture content, density, and pellet durability index (PDI) of wood pellets, and to identify the optimal ratio that yields the most desirable pellet quality. The… More >