Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
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Physico-Mechanical Characteristics of Bast Fibres of Sesamum indicum and Sesamum radiatum for Bioprospecting
Ancy S Watson, Suhara Beevy S
 doi: 10.1016/j.jobab.2022.07.003
[Abstract](10) [PDF 4639KB](2)
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Natural fibres are renewable, inexpensive and biodegradable sources of sustainable materials from plants or animals. Bast fibres, as the notable natural fibres, are gathered from the outer cell layers of the stem of plant. Mature and young bast fibres from two species of Sesamum, namely Sesamum indicum L. and S. radiatum Schumach. & Thonn. were extracted through traditional water retting technique and analyzed for their physical, mechanical and chemical attributes. Anatomical studies revealed polygon shaped phloem (bast fibre) cells with small lumen were similar to jute, in terms of architecture, and bagasse, in terms of lumen size. Upon extraction and subsequent drying, the young stems of S. radiatum were found to yield more bast fibres by mass compared with the rest of the Sesamum samples, that was, 0.59 g (dry weight) of bast fibres from 100 g (fresh weight) of stem. According to stereo microscopic images, the mature S. radiatum fibres had rougher edges than the rest. Both S. indicum and S. radiatum fibre surfaces also seemed to have pores, according to scanning electron microscopy (SEM) images. The porosity appeared to get more pronounced as the plants got older. The Sesamum bast fibres were also found to be extremely hydrophilic with a high-water retention value. The fibres obtained from S. radiatum were determined to be suitable for the textile industry due to their light colour, ideal diameter and length, and water-holding capacity that matched the requirements of fabric manufacturing. Even in the absence of a mordant, the mature fibres showed a significant degree and evenness of Alizarin dye attachment, which might be correlated to the increase in fibre surface roughness with fibre maturity. These fibres were also discovered to be comparable with jute in terms of phloem cell shape (polygonal), diameter (13–15 m), tenacity (12.86–32.54 gf/(g·km–1)), and linear density (2.5–3.3 g/km). It suggested that they might find industrial applications if further research were to be done.
Alternative Wood Treatment with Blends of Linseed Oil, Alcohols and Pyrolysis Oil
Jost Ruwoldt, Kai Toven
 doi: 10.1016/j.jobab.2022.07.002
[Abstract](20) [PDF 2083KB](1)
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Linseed oil is a common wood treatment agent, which is often blended with naphthenic oil during its application. In this study, we developed new types of linseed oil blends, where the naphthenic oil was substituted with alcohols and pyrolysis oil. As miscibility tests revealed, linseed oil can be blended indefinitely with primary alcohols containing three carbon atoms or more. In addition, kinetic stability of three-component-mixtures was found, which comprised linseed oil, alcohol and pyrolysis oil. The developed blends were further tested for their viscosity and rate of solvent evaporation. At last, trial impregnations of wood were done to test this new treatment agent. The uptake of treatment oil and the effect on water repellency varied, and substituting white spirit with propanol and pyrolysis oil showed potential. The latter were miscible with 50% (wt) linseed oil at concentrations of 37.5% 1- or 2-propanol and 12.5% pyrolysis oil. Compared with the reference case, treatment with this agent markedly decreased the water-uptake of the wood. Our study hence attributes great potential to the newly developed linseed oil blends, which may introduce additional product characteristics and generate value to byproducts via pyrolysis.
Preparation and Properties of Hydrophobic and Transparent Wood
Linhu Ding, Xiaoshuai Han, Lian Chen, Shaohua Jiang
 doi: 10.1016/j.jobab.2022.02.001
[Abstract](31) [PDF 1898KB](3)
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Natural wood (NW) was treated with sodium chlorite to obtain delignified wood (DW) in this study, then epoxy was impregnated to get transparent wood (TW), and finally the TW was coated with perfluorodecyltriethoxysilane (FAS) to acquire hydrophobic and transparent wood (HTW). The hydroxyl group generated by the hydrolysis of the FAS and the hydroxyl group of the epoxy underwent a dehydration condensation reaction to generate a Si-O-C bond, while the FAS molecules were also dehydrated and condensed to form a Si-O-Si bond according to Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). Therefore, the mechanical property and thermal stability of the HTW were better than the TW based on their tensile tests and thermogravimetric analysis (TGA). Due to the large reduction of hydroxyl in epoxy, the hydrophobicity of the HTW was greatly improved compared with the TW, and their contact angles were 113° and 77°, respectively. The results of scanning electron microscopy (SEM) showed that epoxy was filled in the voids of wood. In addition, the coating of the FAS did not obviously reduce the transmittance, and the transmittance of the TW and HTW was 69% and 67% at 750 nm. All in all, the HTW has potential for application in transparent decoration.
Dynamical mechanical behaviors of rubber-filled wood fiber composites with urea formaldehyde resin
Feiyu Tian, Xinwu Xu
 doi: 10.1016/j.jobab.2022.05.004
[Abstract](23) [PDF 1835KB](1)
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Wood composites glued with thermosetting synthetic resins tend to show inadequate damping performance caused by the cured resinous matrix. Waste rubber maintains prominent elasticity and is feasible to be an optional modifier. To that end, composite panels of granulated tire rubber (GTR) powders and thermal-mechanically pulped wood fibers were fabricated in this study. Urea formaldehyde (UF) resin was applied as the bonding agent (10% based on wood/rubber total weight). Dynamical mechanical analysis (DMA) was conducted to disclose the thermomechanical behaviors of the rubber-filled wood fiber composites. Influence of two technical parameters, i.e., GTR powder size (0.55-1.09 mm) and addition content (10%, 20% and 30% based on wood/rubber total weight), was specifically discussed. The results showed that storage modulus (E') of the rubber-filled composite decreased while loss factor (tan δ) increased monotonously along with elevated temperature. A steady "plateau" region among 110-170℃ was found where both E' and tan δ keep constant. Accordingly, tan δ showed two peak values at 103-108 and 231- 233℃ due to glass transition of lignin and thermal degradation of hemicellulose, respectively. Addition of rubber fillers resulted in lower bending and internal bonding strengths as well as storage modulus values. When the temperature was above 183℃, all the rubber-filled composites showed higher tan δ values than the control. The findings above fully demonstrate the improved damping performance of the UF-bonded wood fiber composites on account of rubber component. Further work is still needed to optimize the rubber/fiber interfacial bonding strength.
Nanocellulose and its derived composite electrodes toward supercapacitors: Fabrication, properties, and challenges
Junlei Xiao, Huiling Li, Hua Zhang, Shuijian He, Qian Zhang, Kunming Liu, Shaohua Jiang, Gaigai Duan, Kai Zhang
 doi: 10.1016/j.jobab.2022.05.003
[Abstract](45) [PDF 9244KB](2)
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With the increasing demand for sustainable energy storage systems, the development of various advanced materials from a renewable source is imminent. Owing to the advantages of high specific surface area, unique nanostructure, modifiability, and excellent mechanical strength, nanocellulose integrated with other conductive materials, such as nanocarbons, conducting polymers, and metal oxides, has been emerged as promising candidate materials for green and renewable energy storage devices. Besides, nanocellulose-derived carbon materials with good electrical conductivity and tunable microstructures can be fabricated via simple carbonization, which has been widely used as supercapacitor electrode materials. Herein, we present a comprehensive review that focuses on the development of nanocellulose materials for sustainable energy storage, particularly on supercapacitors. The fabrication strategies of nanocellulose-derived hybrid materials are first presented and summarized, followed by highlighting the use of natural nanocellulose for constructing composite electrode materials including two-dimension film electrodes, and three-dimension aerogel electrodes for supercapacitors. In addition, the possible limitations and potentials of nanocellulose in supercapacitors are outlooked.
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Mini Review
Plastic crisis underscores need for alternative sustainable-renewable materials
Su Shiung Lam, Changlei Xia, Christian Sonne
2022, 7(3): 145-147.   doi: 10.1016/j.jobab.2022.06.001
[Abstract](83) [FullText HTML](40) [PDF 285KB](16)
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Review
High-fructose corn syrup production and its new applications for 5-hydroxymethylfurfural and value-added furan derivatives: Promises and challenges
Aristide Laurel Mokale Kognou, Sarita Shrestha, Zihua Jiang, Chunbao (Charles) Xu, Fubao Sun, Wensheng Qin
2022, 7(3): 148-160.   doi: 10.1016/j.jobab.2022.03.004
[Abstract](47) [FullText HTML](19) [PDF 2273KB](6)
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High fructose corn syrup has been industrially produced by converting glucose to fructose by glucose isomerases, tetrameric metalloenzymes widely used in industrial biocatalysis. Advances in enzyme engineering and commercial production of glucose isomerase have paved the way to explore more efficient variants of these enzymes. The 5-hydroxymethylfurfural can be produced from high fructose corn syrup catalytic dehydration, and it can be further converted into various furanic compounds chemically or biologically for various industrial applications as a promising platform chemical. Although the chemical conversion of 5-hydroxymethylfurfural into furanic compounds has been extensively investigated in recent years, bioconversion has shown promise for its mild conditions due to the harsh chemical reaction conditions. This review discusses protein engineering potential for improving glucose isomerase production and recent advancements in bioconversion of 5-hydroxymethylfurfural into value-added furanic derivatives. It suggests biological strategies for the industrial transformation of 5-hydroxymethylfurfural.
Research Article
Effects of a poly(hydroxyalkanoate) elastomer and kraft pulp fibres on biocomposite properties and three-dimensional (3D) printability of filaments for fused deposition modelling
Sandra Rodríguez-Fabià, Gary Chinga-Carrasco
2022, 7(3): 161-172.   doi: 10.1016/j.jobab.2022.03.002
[Abstract](42) [FullText HTML](18) [PDF 3968KB](8)
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Three-dimensional (3D) printing is a useful technique that allows the creation of objects with complex structures by deposition of successive layers of material. These materials are often from fossil origin. However, efforts are being made to produce environmentally friendly materials for 3D printing. The addition of lignocellulosic fibres to a polymer matrix is one of the alternatives to replace, for instance, glass fibres in composites as reinforcing materials. The fields of biocomposites and 3D printing open innovative application areas for pulp fibres from the pulp and paper industry. In this work, biocomposites of poly(lactic acid) (PLA), poly(hydroxyalkanoate) (PHA) and kraft pulp fibres were prepared in order to find a suitable formulation for filaments for 3D printing. The effect of two different types of kraft fibres (bleached (B) and unbleached (U)) and of PHA on the mechanical and thermal properties of the biocomposites was assessed. The addition of 30% kraft fibres to PLA resulted in an increase of the tensile modulus from 3074 to ~4800 MPa. In the case of biocomposites containing PHA (50% PLA/20% PHA/30% kraft) the increase in modulus was more moderate (PLA+PHA+U: 3838 MPa, and PLA+PHA+B: 3312 MPa). The tensile strength of PLA (66 MPa) increased to 77 MPa in PLA+kraft biocomposites, while a reduction in strength was observed for PLA+PHA+U (43 MPa) and PLA+PHA+B (32 MPa). Filaments prepared with PLA, PHA and bleached and unbleached pulp fibres showed similar printability of complex geometries, demonstrating that unbleached pulp fibres could also be utilized in the preparation of biocomposites with good mechanical performance and 3D printing properties.

Mechanism of selective hydrolysis of alginates under hydrothermal conditions
Taku Michael Aida, Yasuaki Kumagai, Smith Jr Richard Lee
2022, 7(3): 173-179.   doi: 10.1016/j.jobab.2022.04.001
[Abstract](28) [FullText HTML](9) [PDF 1064KB](2)
Abstract:

Mechanisms of selective hydrolysis of alginates under hydrothermal conditions were investigated by comparing reactivities of sodium alginate (Na-ALG, 960 ku) solutions and calcium alginate (Ca-ALG) gels as substrates. Under hydrothermal conditions (150 ℃), hydrolysis of Na-ALG gave product molecular weights of 223, 66, 26 and 17 ku while those of Ca-ALG gave product molecular weights of 340, 102, 45 and 31 ku for reaction times of 10, 20, 30 and 60 min, respectively. The ratios of mannuronic acid (M) to guluronic acid (G) varied only slightly (from 1.3 to 1.2) for Na-ALG over the range of reaction times at 150 ℃, while ratios (M/G) for Ca-ALG exhibited a remarkable decrease (from 1.1 to 0.8). Diad sequence of alginate products obtained for Na-ALG were 17%, 23%, 27% and 31% (GG); 30%, 32%, 36% and 38% (MM); and 53%, 46%, 37% and 32% (GM+MG); while for Ca-ALG they were 18%, 22%, 24% and 33% (GG); 26%, 23%, 26% and 18% (MM); and 56%, 54%, 50% and 48% (GM+MG). Reaction mechanisms are proposed for hydrolysis of alginate solutions and alginate gels under hydrothermal conditions; de-polymerization of alginates into monomers and monomeric sequences can be controlled not only by hydrothermal conditions, but also by varying the physical state (solution, gel) of the starting materials.

Evaluating process of auto-hydrolysis prior to kraft pulping on production of chemical pulp for end used paper-grade products
Wenchao Jia, Miaofang Zhou, Chenfeng Yang, He Zhang, Meihong Niu, Haiqiang Shi
2022, 7(3): 180-189.   doi: 10.1016/j.jobab.2022.05.002
[Abstract](28) [FullText HTML](6) [PDF 1281KB](4)
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The objective of this work is to systematically evaluate the performance of the hydrolysis-based kraft pulping process and associated pulp and black liquor characteristics. Acacia wood chips were auto-hydrolyzed under various severities, then the hydrolyzed wood chips were kraft pulping. The results indicated that the yield of pulp significantly dropped with intensifying the auto-hydrolysis severity. Meanwhile, the removal rate of pentosan reached 98.6% in the screened pulp at the P-factor of 1 000. The fiber length, fines and fiber crimp of the screened pulp were not affected by the auto-hydrolysis treatment. Auto-hydrolyzed pulps deteriorated fibrillation and beating response of the pulp in a refining process. However, fiber length and fines changed obviously after beating treatment. After auto-hydrolysis, the tensile index of the paper matrices decreased, some particle substances were found on the surface of the pulp fiber, and the solid and organic content of the black liquor were improved.

Characterization of natural fiber from manau rattan (Calamus manan) as a potential reinforcement for polymer-based composites
Linhu Ding, Xiaoshuai Han, Lihua Cao, Yiming Chen, Zhe Ling, Jingquan Han, Shuijian He, Shaohua Jiang
2022, 7(3): 190-200.   doi: 10.1016/j.jobab.2021.11.002
[Abstract](27) [FullText HTML](11) [PDF 1804KB](2)
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Researches on novel natural fibers in polymer-based composites will help promote the invention of novel reinforcement and expand their possible applications. Herein, in this study, novel cellulosic fibers were extracted from the stem of manau rattan (Calamus manan) by mechanical separation. The chemical, thermal, mechanical and morphological properties of manau rattan fibers were comprehensively analyzed and studied by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) analysis, thermogravimetric analysis (TGA), single fiber tensile test and scanning electron microscopy (SEM). Component analysis results showed that the cellulose, hemicellulose and lignin contents of C. manan fibers were 42wt%, 20wt%, and 27wt%, respectively. The surface of the rattan fiber was hydrophilic according to the oxygen/carbon ratio of 0.49. The C. manan has a crystalline index of 48.28%, inducing a maximum degradation temperature of 332.8 ℃. This reveals that it can be used as a reinforcement for thermoplastic composites whose operating temperature is below 300 ℃. The average tensile strength can reach (273.28 ± 52.88) MPa, which is beneficial to improve the mechanical properties of rattan fiber reinforced composites. The SEM images displayed the rough surface of the fiber, which helped to enhance the interfacial adhesion between the fibers and matrices in composites. These results indicate the great potential of C. manan fibers as the reinforcement in polymer-based composites.

Effects of chitin nanocrystals on coverage of coating layers and water retention of coating color
Ruoshi Gao, Yi Jing, Yeyan Ni, Qiwen Jiang
2022, 7(3): 201-210.   doi: 10.1016/j.jobab.2021.11.003
[Abstract](33) [FullText HTML](15) [PDF 2434KB](4)
Abstract:

This study assessed the applicability of chitin nanocrystals prepared by 2, 2, 6, 6-Tetramethyl-1-Piperidine-1-oxyl radical (TEMPO)-mediated oxidation in traditional papermaking coating color systems. The α-chitin nanocrystals (CTNCs) with different carboxyl content, size, and morphology were prepared from crab shells by alkali pretreatment and TEMPO-mediated oxidation in the water at pH 10, and then the ratio of CTNCs to latex was applied to traditional coating color system to replace part of latex. The results showed that when the amount of NaClO added as co-oxidant in the oxidation was 15.0 mmol/g of chitin, the carboxyl content of alkali-pretreated CTNCs was up to 0.76 mmol/g. The amount of carboxyl groups presented a linear relation with the degree of individualization of nanocrystals and dispersion. When the ratio of latex to CTNCs was 90꞉10, the water retention value of the coating was 92% lower than that of the pure latex system, and the rheological property was better. The relationship between the addition amount of CTNCs and the surface strength and the coverage of coating layers were also studied, and results showed that when the ratio of latex to CTNCs was 95꞉5, the surface strength was the highest of 1.45 m/s, and the coverage of coating layers rate reached the highest of 78%.

Optimizing yield and chemical compositions of dimethylsulfoxide-extracted birchwood xylan
Mingquan Zhang, Jamshed Bobokalonov, Abduvali Dzhonmurodov, Zhouyang Xiang
2022, 7(3): 211-219.   doi: 10.1016/j.jobab.2022.07.001
[Abstract](14) [FullText HTML](20) [PDF 1555KB](4)
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Dimethylsulfoxide (DMSO) extraction is commonly used to study the chemical structures of original xylan in the plant cell wall, since the DMSO can preserve the original structure of the xylan as much as possible during the extracting process. In addition, the DMSO-extracted xylans have unique properties allowing their potential applications in emulsifying or filming materials. However, the yield of DMSO-extracted xylan is always low and the effects of different DMSO extraction conditions on the chemical compositions of xylan have not been fully studied, which greatly hinders its researches and applications. In this study, we have found that extensive delignification before DMSO extraction results in destruction of lignin-carbohydrate complex (LCC), leading to xylan yield and xylose unit content increased by up to 220% and 20%, respectively. Tert-butanol washing of the holocellulose can further increase the DMSO extracted xylan yield by ∼10%. The yield of xylan extracted by the DMSO at 80 ℃ for 7 h was obviously higher than that at room temperature for 3 d by 30%–40%. Thermal analysis showed that the xylans extracted at different conditions had thermal stability without obvious differences. The results indicate that the DMSO-extracted xylan with a high yield, a high purity and a high degree of acetylation can be extracted at a high delignification level, a high reaction temperature and a short reaction time. This study is of great significance for studying xylan structure-property relationships and promoting the applications of DMSO-extracted xylan.

Current Issue

Year 2022 Vol. 7 No.3

Table of Contents

CN32-1890/S7

ISSN 2369-9698

J. Bioresour. Bioprod.

Quarterly

Started in 2016

Editor-in-chief
Huining Xiao, Prof.

University of New Brunswick, Canada

 

Jianchun Jiang, Prof.

Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, China