Biodegradable Wood Research Articles

Development and characterization of sustainable biodegradable wood adhesive using starch as the main ingredient

Development and characterization of sustainable biodegradable wood adhesive using starch as the main ingredient

A strong and biodegradable wood particles-based bioplastic modified by synergistically dynamic cross-linking with tannic acid and Fe3+

The widespread use of petrochemical plastics has caused surging environmental problems and health hazard. Fabrication of biodegradable, eco-friendly and high-performance bioplastic with a facile and efficient way to replace petrochemical materials remains an enormous challenge. As low-cost and abundant sustainable materials, wood particles have the advantages of good processing performance and have been widely studied recently. Herein, a new high-performance sustainable bioplastic was constructed with delignified wood particles (DWP) matrix and enhanced by tannic acid (TA) crosslinked Fe3+ through hot-pressing process. The synergy of dynamic hydrogen bonds and coordination bonds endowed the resultant DWP-based bioplastic with a high tensile strength of 57.5 ± 3.17 MPa that surpassed those of most bioplastics and satisfactory water resistance. Moreover, the resulting film remained more than 94% mechanical properties after staying in harsh conditions for a long time, displaying excellent stability. Furthermore, the DWP/TA/Fe3+ film also demonstrated unique transparency (an average transmittance of 46.74%), decent antioxidant capacity and outstanding biodegradability. In addition, a laminated composite from the DWP-based films and PVA adhesive showed an excellent tensile strength of 70.42 ± 4.52 MPa, higher than some natural woods, which was helpful to expand the industrial application of DWP-based bioplastic. This approach provides a promising pathway for developing strong and sustainable bioplastics with low-cost and abundant biomass sources, and help the development of high-performance bioplastics in the field of disposable tableware, green films and packing materials.

Investigations on mechanical properties of wood composite for sustainable manufacturing

The additive manufacturing technique is foreseen to be the future of the manufacturing industries as it reduces material wastage and enables the machining of intricate shapes. Likewise, the unavailability of skilled laborers has drastically affected the engineering sector. Similarly, the high initial cost and biodegradability issues with the currently seen thermosetting polymer-based 3D printers limit their usage over the long run. Therefore, it is necessary to find better environment friendly alternatives that are renewable and sustainable. This paper proposes a wood powder-binder composite material for potential use in additive manufacturing systems and the preliminary results are presented. A study on the various mechanical properties of the prepared biodegradable wood powder-binder composite material is carried out. This methodology finds application in pattern making and prototyping.

Biodegradable wood plastic composites with phase change microcapsules of honeycomb-BN-layer for photothermal energy conversion and storage

A novel thermal energy storage (TES) composites system consisting of the microPCMs based on n-octadecane nucleus and SiO2/honeycomb-structure BN layer-by-layer shell as energy storage materials, and wood powder/Poly (butyleneadipate-co-terephthalate) (PBAT) as the matrix, was created with the goal of improving the heat transmission and photothermal responsiveness of building materials. The microPCMs were made via mini-emulsion interfacial polycondensation and electrostatic self-assembly to anchor BN on the surface of the SiO2 shell. The two kinds of microPCMs we designed had regular spherical morphology, BN was successfully anchored outside the SiO2 shell, showing a honeycomb structure and good heat storage performance (140.4 J/g and 140.6 J/g). The thermal energy storage wood plastic composites (TES WPCs) had considerable energy storage capacity and temperature regulation ability. The TES WPCs with the unique honeycomb structure of BN-MicroPCMs (BN-WPC) had better heat transfer performance and photothermal conversion efficiency (69.54%), and the thermal conductivity, specific heat capacity and energy storage efficiency of which were increased by 75.06%, 87.06% and 200% respectively. Meanwhile, the unique honeycomb structure strengthened the interfacial bond strength of TES WPCs and brought satisfactory mechanical strength, and the tensile strength, elongation at break, bending strength and bending modulus of BN-WPC are increased by 51.16%, 97.01%, 81.28% and 742.74%, respectively compared with the WPC added with S-MicroPCMs (S-WPC). These results indicated that this research by designing the BN honeycomb structure layer on the traditional microPCMs surface, obtained the rapid thermal response of high-performance TES WPCs in residential construction, thermal energy storage, solar energy collection system and thermal regulation has broad application prospects.

Surface Plasmon-Coupled Dual Emission Platform for Ultrafast Oxygen Monitoring after SARS-CoV-2 Infection

The outbreak of the COVID-19 pandemic has had a major impact on the health and well-being of people with its long-term effect on lung function and oxygen uptake. In this work, we present a unique approach to augment the phosphorescence signal from phosphorescent gold(III) complexes based on a surface plasmon-coupled emission platform and use it for designing a ratiometric sensor with high sensitivity and ultrafast response time for monitoring oxygen uptake in SARS-CoV-2-recovered patients. Two monocyclometalated Au(III) complexes, one having exclusively phosphorescence emission (λPL = 578 nm) and the other having dual emission, fluorescence (λPL = 417 nm) and phosphorescence (λPL = 579 nm), were studied using the surface plasmon-coupled dual emission (SPCDE) platform for the first time, which showed 27-fold and 17-fold enhancements, respectively. The latter complex having the dual emission was then used for the fabrication of a ratiometric sensor for studying the oxygen quenching of phosphorescence emission with the fluorescence emission acting as an internal standard. Low-cost poly (methyl methacrylate) (PMMA) and biodegradable wood were used to fabricate the microfluidic chips for oxygen monitoring. The sensor showed a high sensitivity with a limit of detection ∼ 0.1%. Furthermore, real-time oxygen sensing was carried out and the response time of the sensor was calculated to be ∼0.2 s. The sensor chip was used for monitoring the oxygen uptake in SARS-CoV-2-recovered study participants, to assess their lung function post the viral infection.

Contribution to a Circular Economy Model: From Lignocellulosic Wastes from the Extraction of Vegetable Oils to the Development of a New Composite.

The present works focuses on the development of a novel fully bio-based composite using a bio-based high-density polyethylene (Bio-HDPE) obtained from sugar cane as matrix and a by-product of extraction of chia seed oil (CO) as filler, with the objective of achieving a circular economy model. The research aims to revalorize an ever-increasing waste stream produced by the growing interest in vegetable oils. From the technical point of view, the chia seed flour (CSF) was chemically modified using a silane treatment. This treatment provides a better interfacial adhesion as was evidenced by the mechanical and thermal properties as well as field emission scanning electron microscopy (FESEM). The effect of silane treatment on water uptake and disintegration rate was also studied. On the other hand, in a second stage, an optimization of the percentage of treated CSF used as filler was carried out by a complete series of mechanical, thermal, morphological, colour, water absorption and disintegration tests with the aim to evaluate the new composite developed using chia by-products. It is noteworthy as the disintegration rate increased with the addition of CSF filler, which leads to obtain a partially biodegradable wood plastic composite (WPC) and therefore, becoming more environmentally friendly.

Experimental and numerical study on mechanical behavior and resistance to natural weathering of sugarcane leave reinforced polymer composite

The waste sugarcane dry leaves were utilized as the reinforcement with the epoxy matrix to prepare the sugarcane dry leaves reinforced polymer composites (SDLRPCs). The tensile, compressive, impact and flexural tests were conducted following respective ASTM standards. The proportion of SDL in SDLRPCs for the most effective fiber–matrix interaction was determined. The statistical analysis has confirmed that the error in experimental results was within the specified limits. The resistance to natural weathering of SDLRPCs were evaluated following ASTM D5338-11. The effect of weathering on tensile strength was also investigated. The scanning electron microscopy (SEM) micrographs revealed reasons for fracture of SDLRPC samples during mechanical testing. It was noticed that the biodegradability corresponds with resistance to natural weathering; more biodegradable wood plastic composites were having the lesser resistance to natural weathering. The micromechanical finite element (FE) model coupled with the numerical homogenization technique (NHT) was constituted to predict the elastic properties of SDLRPCs. The micro-scale stress analysis revealed that the von Mises stress for SDLRPC was up to 267% higher than the pure epoxy. The transient/static micro-mechanical models were constituted to predict the tensile, compressive, impact, and flexural behavior of SDLRPCs. The developed models were found in-line with the experimental data.

Sustainable and Biodegradable Wood Sponge Piezoelectric Nanogenerator for Sensing and Energy Harvesting Applications.

Developing low-cost and biodegradable piezoelectric nanogenerators is of great importance for a variety of applications, from harvesting low-grade mechanical energy to wearable sensors. Many of the most widely used piezoelectric materials, including lead zirconate titanate (PZT), suffer from serious drawbacks such as complicated synthesis, poor mechanical properties (e.g., brittleness), and toxic composition, limiting their development for biomedical applications and posing environmental problems for their disposal. Here, we report a low-cost, biodegradable, biocompatible, and highly compressible piezoelectric nanogenerator based on a wood sponge obtained with a simple delignification process. Thanks to the enhanced compressibility of the wood sponge, our wood nanogenerator (15 × 15 × 14 mm3, longitudinal × radial × tangential) can generate an output voltage of up to 0.69 V, 85 times higher than that generated by native (untreated) wood, and it shows stable performance under repeated cyclic compression (≥600 cycles). Our approach suggests the importance of increased compressibility of bulk materials for improving their piezoelectric output. We demonstrate the versatility of our nanogenerator by showing its application both as a wearable movement monitoring system (made with a single wood sponge) and as a large-scale prototype with increased output (made with 30 wood sponges) able to power simple electronic devices (a LED light, a LCD screen). Moreover, we demonstrate the biodegradability of our wood sponge piezoelectric nanogenerator by studying its decomposition with cellulose-degrading fungi. Our results showcase the potential application of a wood sponge as a sustainable energy source, as a wearable device for monitoring human motions, and its contribution to environmental sustainability by electronic waste reduction.

Research of biodegradable wood completed composite materials based on polylactide

Experimental samples of biodegradable composite material based on polylactide and wood filler, subjected to thermal modification, were obtained. When studying the samples a change in such properties as the rate of biodegradation and tensile strength was observed. It has been established that the degree of preliminary thermal treatment of wood filler can control the rate of biodegradation in the material, which can be used in the production of biodegradable packaging. Depending on the desired product life cycle, packages with an adjustable decomposition time can be created. It is found that with an increase in the degree of heat treatment of the filler in a composite material with more than 40 % of polylactide the tensile strength decreases, while with a lower binder content thermal modification has a positive effect on the strength. Also, adding the fillers can significantly reduce the cost of composite material.

Green, economic, and partially biodegradable wood plastic composites via enzymatic surface modification of lignocellulosic fibers

Lignocellulosic fibers, which obtained from Citrus trees trimmings, were modified with Aspergillus flavus (EGYPTA5) enzymes. The non-modified and the modified lignocellulosic fibers were used with low density polyethylene (LDPE) by melt blending brabender method at 170 °C with different ratio (5, 10 and 20 wt%) to obtain wood plastic composites (WPC). The prepared samples were characterized using Fourier-transformed infrared (FT-IR), Scan Electron Microscope (SEM), and Water vapor transmission rate (WVTR) as well as, the mechanical, thermal, biodegradability and swelling properties were examined. The fabricated WPC displayed good mechanical and thermal properties compare with pure LDPE. Also, the WVTR was enhanced by the addition of modified lignocellulosic fibers over the unmodified one. Moreover, the enzymes assay such as cellulase and lignin peroxidase enzymes were estimated and confirming the growing of fungi on the lignocellulosic fiber in solid state fermentation condition to improve lignin peroxidase production and eliminate cellulose enzymes. The fabricated WPC can be used in different environmental application such as packaging system, that it will be green, economic, and partially biodegradable.

A Study on Wet and Dry Tensile Properties of Wood pulp/Lyocell Wetlace Nonwovens

A new biodegradable wood pulp/Lyocell moist wipe had been developed, which made from wetlaid/spunlace(wetlace) technology. The dry and wet tensile curve characteristics were described and the relationship between dry and wet strength in both machine direction (MD) and cross-machine direction (CD) were investigated. The results indicate that the fabricated wetlace materials are composed of the entanglements and cohesions of wood pulp/Lyocell fibres. The modulus and tensile strength of the materials were obviously decreased in wet state, and the tensile curves in the dry and wet state both can be divided into two parts. It is noted that there exists a high linear correlation between the dry and wet strength in MD or CD. Meanwhile, the diminished amplitude of wet strength in CD is larger than that of wet strength in MD and the relationship fluctuation between the wet and dry strength in CD is significantly higher than that in MD.

Fully biodegradable modification of wood for improvement of dimensional stability and water absorption properties by poly(ε-caprolactone) grafting into the cell walls

Materials derived from renewable resources are highly desirable in view of more sustainable manufacturing. Among the available natural materials, wood is one of the key candidates, because of its excellent mechanical properties. However, wood and wood-based materials in engineering applications suffer from various restraints, such as dimensional instability upon humidity changes. Several wood modification treatments increase water repellence, but the insertion of hydrophobic polymers can result in a composite material which cannot be considered as renewable anymore. In this study, we report on the grafting of the fully biodegradable poly(e-caprolactone) (PCL) inside the wood cell walls by Sn(Oct)2 catalysed ring-opening polymerization (ROP). The presence of polyester chains within the wood cell wall structure is monitored by confocal Raman imaging and spectroscopy as well as scanning electron microscopy. Physical tests reveal that the modified wood is more hydrophobic due to the bulking of the cell wall structure with the polyester chains, which results in a novel fully biodegradable wood material with improved dimensional stability.

Hot embossing and thermoforming of biodegradable three-dimensional wood structures

Hot embossing allows for low cost fabrication of nanostructures with highest aspect ratios on large surfaces and is commonly based on a large variety of polymers. The widespread use of nanostructured materials, however, poses environmental challenges. Here, we show that biodegradable wood from renewable resources can be structured on the nano-scale and that surface characteristics can be imprinted and three-dimensionally formed. In particular, we show that so-called liquid wood made out of lignin can be structured with feature sizes down to 100–200 nm and three dimensionally shaped by microthermoforming. We demonstrate optical active surfaces by diffractive elements, the change of hydrophobic to super-hydrophobic behavior and the fabrication of super-hydrophobic microfluidic channels. Based on these results we anticipate new applications in the nano- and micro-range, particularly for use in sensitive environments without posing a risk to nature. The new compound material will allow for a substitution of conventional polymers used as material in one way applications of e.g. the consumer, the food or the disposable medical industry.

Effects of Sodium Bisulfite on the Physicochemical and Adhesion Properties of Canola Protein Fractions

This study focused on investigating the potential of using canola protein fractions as bio-degradable wood adhesives. Native and sodium bisulfite (NaHSO3)-modified canola protein fractions isolated successively at different pH values (7.0, 5.5, and 3.5) was used as adhesives. Wood specimens were assembled with adhesives at a pressure of 2 MPa at 150, 170, or 190 °C for 10 min. The adhesion performance of adhesives were evaluated by wet, soak, and dry shear strength. Their physicochemical properties: extractability, electrophoresis profiles, thermal, rheological and morphological properties were also characterized. Results showed that canola protein had the highest protein yield and purity at pH 5.5. Electrophoresis profile proved that NaHSO3 cleaved the disulfide bonds in canola protein. This could induce extra charges (RS-SO3 −) on the protein surface, leading to the reduced apparent viscosity. Thermal analysis implied that the thermal transition temperature of canola protein decreased with modification of NaHSO3. Canola protein adhesives showed excellent dry and soak shear strength with 100 % wood cohesive failure in all curing temperatures. The wet adhesion strength of native and modified canola protein fraction adhesives at pH 5.5 and pH 3.5 (3.9–4.1 MPa) was higher than the fractions at pH 7.0. NaHSO3 had insignificant effects on the adhesion performance of canola protein adhesives but notably improved the handling and flow-ability properties of canola protein adhesives.

Development of Biodegradable Wood Fiber Foam Packaging Material

. In daily life, expanded polystyrene foams (EPS) are widely used as packaging material and waste EPS has caused lots of environmental pollutions because it cannot be decomposed in nature. In this study, the machining process is developed of a reinforced foam packaging material by hot press molding, potato starch and birch fiber as the main raw materials. Analysis of the dosage of the birch fiber, starch adhesive and foaming agent and how do they affect the mechanical properties. Experiments show that material compressive strength is good and foam well-distributed, when the birch fiber content is 20%-25%, adhesive content is 30%-35%, and birch fiber amount is 10%-15%, the material has fine performance, and the cells are well distribute.

Fabrication and characterization of biodegradable poly(propylene carbonate)/wood flour composites

AbstractWood flour reinforced poly(propylene carbonate) (PPC) composites were prepared by melt blending followed by compression molding. The effects of reinforcement on the morphology, static and dynamic mechanical properties, and thermal properties of PPC/wood flour composites were investigated. In terms of mechanical properties, wood flour had the significant effect of improving tensile strength and stiffness. Scanning electron microscopic examination revealed good dispersion of wood flour (especially at lower content) in the PPC matrix. Moreover, experimental results indicated that the wood flour addition led to an obvious improvement in the thermal stability of the composites. This paper demonstrates that the incorporation of low‐cost and biodegradable wood flour into PPC provides a practical way to produce completely biodegradable and cost‐competitive composites with good mechanical properties. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 782–787, 2006

Preparation, processing and characterization of biodegradable wood flour/starch-cellulose acetate compounds

A novel biodegradable material was prepared by compounding, in different proportions, pine wood flour (WF) and a commercial starch-cellulose acetate blend on a configurable co-rotating twin screw extruder. After pelletizing, the compounds were injection moulded and the mechanical and rheological properties of the mouldings determined. As the content of wood flour increases up to 50% (wt/wt), the tensile strength and the modulus improve significantly, whereas the toughness drops gradually. The effect of the wood flour content on the shear viscosity is complex, being impossible to establish a linear relationship between the two. The shear viscosity decreases with shear rate, but for a level of 40% and 50% of WF there is evidence of a quasi-Newtonian behaviour, irrespective of the test temperature. Compounds with 50% WF present the highest tensile strength and modulus but are difficult to process. However, the processability can be improved by using glycerol as plasticizer, without paying a too severe penalty in mechanical properties. In fact, by adding 15% glycerol (wt/wt), compounds with 50% WF can be successfully injection moulded into specimens with good mechanical properties.

Smoke and Toxic Species Analyses from Controlled Combustion of Wood Impregnated with Guayule Resin

Abstract Dominant commercial treatments currently used for wood preservation are pentachlorophenols (PCPs), creosote, and chromium copper arsenicals (CCAs). These wood preservatives present many studied and documented environmental and toxicological problems both with use of the products themselves and with the production of secondary reaction contaminants. Furthermore, several of these preservatives are considered priority pollutants according to the U.S. Environmental Protection Agency (EPA) and are heavily regulated. The need for an environmentally benign combined fire/rot retardant treatment for wood that will effectively reduce both fire and decay is clearly evident. Guayule resin, a co product during rubber extraction from the guayule shrub, is being explored by us as a natural, biodegradable wood rot and fire retardant with potential commercial applications. Wood impregnated with guayule resin has survived over 8 years in a tropical rain forest environment, free of rot, decay, and insect infestatio...