Poplar Fibers Research Articles

THE EFFECT OF COLORANTS ON THE DEGRADATION PERFORMANCE OF WOOD PLASTIC COMPOSITES

The degradation performance of the colorful wood flour/poly (β-hydroxybutyrate valerate) composites (CWPHBVs) in natural outdoor landfill was investigated by some physical, analytical, and microscopic tests. The mass loss rate of the CWPHBVs within 80 days of degradation shows a growth trend and the mass loss rate decreases by more than 20%. With the increase of degradation time, the bending strength of the CWPHBVs continues to decline, the elastic modulus of the CWPHBVs shows a logarithmic decline trend. After 30 days, the bending strength of the CWPHBVs decreases over 50% and tend to be stable. The colorant has a certain inhibitory effect on the degradation. However, with the shedding of the colorant, the effect of the colorant on the degradation is gradually weakened. The addition of colorants reduces the decomposition rate of PHBV and improves the thermal stability of poplar fibers. However, after 20 days, this effect almost disappears.

Fireballs-Like Explosive Peroxides Produced by the Brown-rot Fungus

Abstract: Fireballs are unusual and rare phenomena usually associated with thunderstorms, although sometimes they have been observed during earthquakes, volcano eruptions or in fair weather. There are still questions about their origination, features and interaction with the environment. In this work, a new model is shown to explain the formation of fireballs in fair weather from poplar cotton and peroxides produced by brown-rot fungi. Light emission is produced via thermal decomposition of 1,2- dioxetane phenylcoumarane or 1,2-dioxetane monolignol, from lignin inside the poplar fibers. The energy released during the explosive decaying of fireballs was calculated as being about 3 kilojoules for each gram. This value is the same order of magnitude as the estimated for the explosive fireballs decaying.

Utilization of poplar fibers in needle punched nonwovens

The focus of this study is to conduct pioneering research on utilizing poplar seed hair fibers in needle punched nonwovens. These fibers were blended with hollow PET fibers at two different weight ratios to obtain needle punched webs for the first time. The weight, thickness, abrasion resistance, bursting and tensile properties, hydrophobic/oleophilic surface characteristics of the nonwovens are analyzed elaborately. Finally, it has been demonstrated that poplar fiber-containing nonwovens have superior rose oil absorption compared to solely PET nonwoven fabrics. When compared the maximum adsorption capacities, the incorporation of 37.3 wt.% and 21.7 wt.% poplar fiber into PET nonwoven increased the oil absorption by approximately 35 and 24 times, respectively. Although pristine PET nonwoven was able to remove only 16% of MB dye from aqueous dye solution, addition of poplar fiber enhanced the removal process and the solution had been decolorized to nearly colorless. The results indicated that poplar blended nonwoven fabrics treated with NaClO2 show the high-performance removal of MB dye from wastewater, with the increased percentage of 40% and 67% for PET-PO30 and PET-PO60 fabric, respectively. Therefore, developing industrial scale surfaces with non-traditional and sustainable poplar seed fibers, marks a significant advancement for the textile industry.

Development of binderless fiberboard from poplar wood residue with Trametes hirsuta

The utilization of agricultural and forestry residues for the development and preparation of green binderless fiberboard (BF) is an effective way to realize high-value utilization of lignocellulose biomass resources. This study focuses on the fabrication of BF with excellent mechanical and waterproof properties, utilizing poplar wood residue (PWR) as raw material and Trametes hirsuta as a pretreatment method. During the fermentation process, lignin-degrading enzymes and biological factors, such as sugars, were produced by T. hirsuta, which activated lignin by depolymerizing lignin bonds and modifying structural functional groups, and forming new covalent bonds between poplar fibers, ultimately enhancing adhesion. Additionally, the activated lignin molecules and sugar molecules coalesce under high temperatures and pressures, forming a dense carbonization layer that bolsters the mechanical properties of the fiberboard and effectively shields it from rapid water infiltration. The bio-pretreated BF for 10 days shows a MOR and MOE of up to 36.1 Mpa and 3704.3 Mpa, respectively, which is 261% and 247.8% higher than that of the bio-untreated fiberboard, and the water swelling ratio (WSR) rate is only 5.6%. Chemical composition analysis revealed that repolymerization occurred among lignin, cellulose, and hemicellulose, especially the molecular weight of lignin changed significantly, with the Mw of lignin increasing from 312066 g/mol to 892362 g/mol, and then decreasing to 825021 g/mol. Mn increased from 277790 g/mol to 316987.5 g/mol and then decreased to 283299.5 g/mol at 21 days. Compared to other artificial fiberboards prepared through microbial pretreatment, the BF prepared by microorganisms in this study exhibited the highest mechanical properties among the poplar wood biobased panels.

Physical and mechanical properties of mycelium-based fiberboards

Mycelium-based fiberboards were evaluated as potential environmentally friendly substitutes for conventional wood-based composites. The goal of this study was to produce and test fiberboards out of yellow pine and poplar fiber mixtures without using any extra adhesive. Pleurotus ostreatus and Ganoderma lucidum fungi were used. The physical and mechanical characteristics of the fiberboards were tested under the influence of two different types of fungi and two different incubation periods. The key findings indicated that the mycelium-based fiberboards had higher water absorption and thickness swelling percentages compared to control boards produced with adhesives. The fiberboards produced from fibers inoculated with Ganoderma lucidum and incubated for 30 days had higher mechanical properties compared to other test fiberboards. This indicated the possibility of utilizing them in specific applications. Although the mycelium-based fiberboards did not fully meet all the EN 622-5 (2009) standard requirements for dry-condition use, the results highlighted their potential in sustainable material development. This study provided useful insights into the utilization of mycelium for the development of mycelium-based fiberboards.

Expression of cellobiose dehydrogenase gene in Aspergillus niger C112 and its effect on lignocellulose degrading enzymes.

Cellobiose dehydrogenase (CDH) is one of the cellulase auxiliary proteins, which is widely used in the field of biomass degradation. However, how to efficiently and cheaply apply it in industrial production still needs further research. Aspergillus niger C112 is a significant producer of cellulase and has a relatively complete lignocellulose degradation system, but its CDH activity was only 3.92 U. To obtain a recombinant strain of A. niger C112 with high cellulases activity, the CDH from the readily available white-rot fungus Grifola frondose had been heterologously expressed in A. niger C112, under the control of the gpdA promoter. After cultivation in the medium with alkali-pretreated poplar fiber as substrate, the enzyme activity of recombinant CDH reached 36.63 U/L. Compared with the original A. niger C112, the recombinant A. niger transformed with Grifola frondosa CDH showed stronger lignocellulase activity, the activities of cellulases, β-1, 4-glucosidase and manganese peroxidase increased by 28.57, 35.07 and 121.69%, respectively. The result showed that the expression of the gcdh gene in A. niger C112 could improve the activity of some lignocellulose degrading enzymes. This work provides a theoretical basis for the further application of gcdh gene in improving biomass conversion efficiency.

Equivalent heat transfer modeling for poplar fiber clusters based on thermography

Equivalent heat transfer modeling for poplar fiber clusters based on thermography

Enhancing interfacial adhesion through coupling agent incorporation in plywood/ plastic waste composite materials

The objective this study was to fabricate 5-ply boards using virgin and recycled high-density polyethylene (vHDPE and rHDPE) films as formaldehyde-free adhesives, respectively. To enhance the interfacial adhesion between the wood veneer and HDPE film, various loadings (0, 3, 6, 8, and 11 wt%) of polyethylene grafted maleic anhydride (PE-g-MA) were applied as a coupling agent. The physical and mechanical performance of the resulting plywood boards was evaluated using standard test methods, with a UF resin-bonded plywood used as a control for comparison. All materials used were for commercial-scale plywood production. Fourier transform infrared spectroscopy (FT-IR) results provided valuable information about chemical interactions that occurred during the coupling of poplar fibers with HDPE using PE-g-MA. The experimental results showed that the mechanical and physical properties of the plywood boards improved as the amount of coupling agent increased from 0 to 11 wt%. PE-g-MA played a crucial role in the properties of plywood boards made with rHDPE and vHDPE by enhancing the interfacial bonding ability between the HDPE and adjacent veneers, leading to good stress propagation and improved mechanical properties. The properties of samples bonded with vHDPE were significantly more improved than those made with rHDPE, likely due to the presence of color pigments, additives, fillers, and impurities in the rHDPE, which made the coupling agent less effective. In addition, the results demonstrated that the samples made with rHDPE and vHDPE were superior to the plywood bonded with UF resin (control), and the optimal content of the coupling agent was found to be 8 and 11 wt%. These findings suggest that incorporating recycled HDPE films and using coupling agents, such as PE-g-MA, can produce high-quality plywood composite materials with improved mechanical and physical properties, providing an eco-friendly alternative to traditional UF resin-bonded plywood.

DETERMINATION OF UREA-FORMALDEHYDE RESIN CONTENT IN POPLAR FIBER BASED ON HYPERSPECTRAL TECHNIQUES

In this experiment, poplar fibers containing 0%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 25% and 30% of urea-formaldehyde resin were prepared. A model for the detection of urea-formaldehyde resin content in poplar fibers was established by the hyperspectral near-infrared imaging system combined with relevant algorithms. The spectral images of poplar fibers containing different contents of urea-formaldehyde (UF) resin were measured separately using hyperspectral imager. The results of four preprocessing methods, namely mean centering (MC), multiple scattering correction (MSC), standard normal variables (SNV) and first-order derivative (1-Der) were analyzed, and the optimal preprocessing method was selected as SNV. The band combinations with the highest correlation with the urea-formaldehyde resin content were compared and analyzed with the full-band model to establish the partial least squares regression (PLSR) model. The experimental results show that the hyperspectral imaging system combined with the corresponding algorithm can achieve rapid detection of UF resin content in poplar fibers, and the results of this study provide technical support and theoretical reference for determination of resin content in ultra-thin fiberboard production. The method is an innovative model for the determination of UF resin in wood fibers.

Thermal and moisture coupling performances of poplar fiber inorganic humidity control brick

• Three-dimensional thermal moisture coupling model of brick was established. • Mass diffusion coefficients were calculated using X-ray transmission techniques. • The thermal diffusivity was positively correlated with the mass diffusivity. • The compressive strength and color change of absorption were experimentally studied. Wood-inorganic composite building materials are an excellent choice for humidity control. This paper uses poplar fiber and calcium hydroxide to hot-press wood inorganic humidity control bricks. A three-dimensional thermal moisture coupling model of biomass bricks is established to predict the hygrothermal behavior. X-ray transmission technology is used to determine mass diffusivity. It is positively correlated with heat diffusivity. The calculated and experimental thermal conductivity values are lower than 0.12 W/(m·K). The biomass bricks can maintain an excellent thermal insulation effect when absorbing moisture. The compressive strength decreases with relative humidity. After 97.4 %RH moisture absorption balance, the compressive strength is 8.03 MPa, which also met the strength requirements of indoor partition walls. The color difference of biomass bricks after 11.3 %RH moisture absorption is more significant than 3.0, which the human eyes can recognize. Moreover, the moisture content of biomass bricks can be estimated according to the change of color difference. The research is better for providing a theoretical basis and technical guidance for the market promotion of humidity control materials and building energy conservation.

Lignin p-Hydroxybenzoylation Is Negatively Correlated With Syringyl Units in Poplar.

The lignin found in the cell walls of poplar fibres is decorated with ester-linked p-hydroxybenzoate moieties that originate from the participation of acylated monolignols in lignin polymerisation. Although little is known about the biological implications of these cell-wall constituents, it has historically been postulated that acylated monolignols might promote lignification in syringyl lignin-rich species such as poplar. However, cell-wall-bound p-hydroxybenzoate groups were negatively correlated with syringyl units in a collection of 316 unrelated genotypes of black cottonwood (Populus trichocarpa). Based upon this observation, several alternative hypotheses on the occurrence of lignin acylation are presented.

Study on the hygroscopic performances of poplar wood fiber biomass brick

Poplar fiber biomass brick is an energy-saving and environmentally friendly biomass building material developed in recent years. It has good hygroscopic performance, can adjust indoor air humidity, helps reduce building energy consumption for dehumidification and humidification, and improves indoor air comfort. This paper studies the hygroscopic performance of poplar fiber brick from the microscopic pore structure experiment, nitrogen physical adsorption experiment, equilibrium moisture content experiment, moisture sorption and desorption cycle experiment, and water vapor transmission experiment. The model of the sorption-desorption curve of poplar fiber biomass brick at 23 °C is established. Moreover, the ideal moisture buffering value (MBV) of poplar fiber brick and the ideal and practical MBV values under the experimental procedures of this article are calculated. The results show that the Peleg model is most suitable for poplar fiber brick's moisture absorption and desorption curve at 23 °C. The MBV value is the “Excellent” level and has good moisture sorption and desorption performance. The obtained data and models provide potent data support for promoting and applying biomass bricks and theoretical model research.

Using LSTM and PSO techniques for predicting moisture content of poplar fibers by Impulse-cyclone Drying.

Impulse-cyclone drying (ICD) is a new type of pretreatment method to remove the excess moisture of wood fibers (WFs) with high speed and low energy consumption. However, the process parameters are often determined by the experience of the process operators, thus the quality of WF drying lacks an objective basis and cannot be ensured. To address this issue, this study adopted the long short-term memory (LSTM) neural network, backpropagation neural network, and Central-Composite response surface method to establish a moisture content (MC) prediction model and a process parameter optimization model based on single-factor experiments. The initial MC, inlet air temperature, feed rate, and inlet air velocity were taken as the experimental factors, and the final MC was taken as the inspection index. The parameters of LSTM were optimized by particle swarm optimization (PSO) algorithm, and the predicted value of MC was fitted to the model. The PSO-optimized LSTM had higher prediction accuracy than did the typical prediction models. The optimal process for the targeted MC, which was obtained by PSO, was featured with an initial MC of 10.3%, inlet air temperature of 242°C, feed rate of 90 kg/h, and inlet air velocity of 8 m/s. PSO-LSTM could be a new approach for predicting the MC of WFs, which, in turn, could provide a theoretical basis for the application of ICD technology in the biomass composite industry.

Initial characteristics of the dried poplar fiber as an accessibility indicator for its enzymatic digestibility in the whole hydrolysis process

Initial characteristics of the dried poplar fiber as an accessibility indicator for its enzymatic digestibility in the whole hydrolysis process

Lignin-Based Phenolic Foam Reinforced by Poplar Fiber and Isocyanate-Terminated Polyurethane Prepolymer.

Phenolic foams (PFs) are lightweight (<200 kg/m3), high-quality, and inexpensive thermal insulation materials whose heat and fire resistance are much better than those of foam plastics such as polyurethane and polystyrene. They are especially suitable for use as insulation in chemical, petroleum, construction, and other fields that are prone to fires. However, PFs have poor mechanical properties, poor abrasion resistance, and easy pulverization. In this paper, a polyurethane prepolymer was treated with an isocyanate, and then the isocyanate-terminated polyurethane prepolymer and poplar powder were used to prepare modified lignin-based phenolic foams (PUPFs), which improved the abrasion resistance and decreased the pulverization of the foam. The foam composites were comprehensively evaluated by characterizing their chemical structures, surface morphologies, mechanical properties, thermal conductivities, and flame-retardant properties. The pulverization ratio was reduced by 43.5%, and the thermal insulation performance and flame-retardancy (LOI) were improved. Compared with other methods to obtain lignin-based phenolic foam composites with anti-pulverization and flame-retardant properties, the hybrid reinforcement of foam composites with an isocyanate-terminated polyurethane prepolymer and poplar powder offers a novel strategy for an environmentally friendly alternative to the use of woody fibers.

Printability and properties of 3D-printed poplar fiber/polylactic acid biocomposite

To efficiently and economically utilize a wood-plastic biocomposite, an eco-friendly biocomposite was prepared using modified poplar fiber and polylactic acid (PLA) via 3D printing technology for the first time. First, the effects of poplar fiber (0, 1, 3, 5, 7, and 9%) on the mechanical and rheological properties of the printed biocomposites were investigated. Subsequently, the printing parameters, including printing temperature, speed, and layer thickness, were optimized to obtain the biocomposite with superior properties. Finally, four printing orientations were applied to the biocomposite based on the optimized printing parameters to study the effect of filament orientation on the properties of the biocomposite. Favorable printability and mechanical properties of the biocomposite were obtained at 5% poplar fiber. The optimal printing temperature of 220 °C, speed of 40 mm/s, and layer thickness of 0.2 mm were obtained to produce the desired mechanical properties of the biocomposite with the printing orientation in a longitudinal stripe. However, the printing parameters should be chosen according to the applications, where different physical and mechanical properties are needed to achieve efficient and economical utilization of the biocomposites.

Effect of phosphate treatment on interfacial properties of poplar fiber/high-density polyethylene composites

Poplar fiber was treated with phosphate solution as a modifier and then wood fiber/high-density polyethylene (HDPE) degradable composite was prepared by melt blending with HDPE. The effects of phosphate solution concentration on tensile strength and flexural strength of composites were investigated. The surface morphology of phosphate-treated poplar fibers was observed by scanning electron microscopy. The results show that the phosphate treatment increases the surface roughness of the poplar fiber, increases the strength of the single fiber, and effectively improves the mechanical adhesion to the HDPE matrix. However, when the phosphate concentration is too large, the density of the cellulose molecular chains is lowered, and the mechanical properties of the whole fiber are lowered. When the concentration of phosphate solution is 3%, the treatment time is 4 h, and the treatment temperature is 60°C, the tensile properties, bending properties, and water resistance of poplar fiber/HDPE composites are the best.

Effect of Steam Explosion Technology Main Parameters on Moso Bamboo and Poplar Fiber

Effect of Steam Explosion Technology Main Parameters on Moso Bamboo and Poplar Fiber

Analysis of the influence of particle and poplar fibres share on selected properties of particle-fibre boards

Analysis of the influence of particle and poplar fibres share on selected properties of particle-fibre boards. As a part of the study, one-layer particle-fibre boards with 12 mm thick and of average density 650 kg/m3 were manufactured from plantation poplar ‘Hybrid 275’ wood.. For the control variant a typical industrial raw material (pine wood) was used. The following properties were determined for the boards: modulus of rapture (MOR), density profile, modulus of elasticity at static bending (MOE), internal bond (IB), thickness swelling (TS) after 2h and 24h soaking in water. On the basis of conducted study, it was found that the addition of poplar fibers to particle-fibre boards in most cases has a positive effect on the values of determined properties – an increase in strength was noted, except for internal bond (IB). In the case of thickness swelling of the boards after 24 h soaking in water, it was noted that with the increase in the share of poplar fibers in the boards, the value of the tested property decreased (which was not clear in the case of thickness swelling of boards after 2 h soaking in water).

Optimization of alkali-treated poplar fiber saccharification using metal ions and surfactants

ABSTRACT In this study, contrary to untreated poplar fiber, processing of alkali-treated poplar fiber was optimized for the enzymatic saccharification. Considering reducing sugar content as the evaluation index, pH, temperature, time, amount of enzyme, and rotational speed of shaker were standardized to optimize the sugar production by enzymatic hydrolysis. Using response surface methodology, the optimum technological condition of enzymatic hydrolysis was found to be utilizing 43 mg cellulase at 46 °C for 50 h. At this, the sugar conversion amount of NaOH or H2O2-NaOH pretreated poplar was 164.62 mg/g and 218.82 mg/g respectively. It was a corresponding increase of 446.73% or 626.75% than that of poplar fiber without a pretreatment. At a low concentration, metal ions and surfactants promoted the conversion of reducing sugar. Especially, 0.01 g/L Mn2+ and 0.50 g/L hexadecyl trimethyl ammonium bromide (CTAB) produced the best effect and increased the conversion rate of reducing sugar by 23.62% and 21.44% respectively. Also, the effect of the combination of metal ions and surfactants was better than that of a single accelerator. By improving the enzymatic process, these findings could enhance the utilization of poplar fiber for the production of reducing sugar.