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Wood flour (WF) at 10 wt.% and 20 wt.% loadings was used as a reinforcing filler to enhance the applicability of polypropylene (PP) for 3D printing. After performing printability tests of PP wood plastic composites (WPCs), the mechanical properties of both injection‐molded and 3D‐printed PP WPC specimens were explored. Test specimens were prepared from 3D printed hexagons for analyzing the mechanical properties. Adding WF to neat PP increased the storage modulus and the glass transition temperature while decreasing the degree of crystallinity and the coefficient of thermal expansion, while enhancing the printability of neat PP. The tensile strength, tensile modulus of elasticity, flexural strength, and flexural modulus of elasticity of injection‐molded neat PP improved by up to 21%, 59%, 30%, and 56%, respectively, with 20 wt.% WF. However, the impact strength of injection‐molded neat PP decreased by 85%, with 20 wt.% WF. After 3D printing, the tensile strength and tensile modulus of elasticity of printed neat PP increased by up to 84% and 60%, respectively, with 20 wt.% WF. The flexural strength and flexural modulus of elasticity of neat printed PP remained unchanged compared to those of PP filled with 20 wt.% WF, while the impact strength decreased by 87%. Highlights: WF was used as a reinforcement in polypropylene designed for 3D printingA pilot‐scale, pellet‐fed 3D printer was used to print hollow hexagons, and then test specimens were fabricated from these hexagons for mechanical propertiesThe tensile and flexural properties of 3D printed neat polypropylene improved, while the impact strength decreased after adding 20 wt.% WF to the neat PP. [ABSTRACT FROM AUTHOR]

This research explores the development of new composite material by integrating Azadirachta Indica (AI) with LLDPE to create wood‐plastic composites using the rotational molding process. By examining various proportions of AI wood flour blended with LLDPE, we investigated their impact on mechanical and physical properties. Our tests elucidate a clear correlation between mechanical properties and composite morphologies. Despite identical molding conditions, higher wood particle concentrations reduced mechanical properties compared to lower concentrations. Remarkably, a 12% wood content emerges as optimal, yielding a tensile modulus of 3.69 MPa and a flexural modulus of 468.5 MPa, with an acceptable reduction of 11% density and 13% porosity versus pure LLDPE. Additionally, we observed declines in tensile strength, impact strength, and hardness by up to 23%, 62%, and 11%, respectively, compared to neat LLDPE. Natural fillers enhance aesthetics, making these materials ideal for consumer products like garden equipment and furniture accessories. [ABSTRACT FROM AUTHOR]

The results of the study of plastic composites from degradable poly(3-hydroxybutyrate) P(3HB) and cellulose-containing natural materials of various origins are presented. For the first time, P(3HB) composites filled with bacterial nanocellulose (BNC) or wood (Pinus sibirica) flour (WF) were produced by melt pressing at 170 °C and 2000 Pa. The influence of the filler type and amount (30, 40, 50, 70 and 90 wt%) on the physicochemical and mechanical properties of the composites and their degradability in soil laboratory microcosms was revealed. The P(3HB)/WF composites compared with P(3HB)/BNC ones were thermally stable; their thermal degradation temperatures were 266 and 227 °C, respectively. Both composites had lower values of Young's modulus and fracture strength compared to P(3HB). As BNC content was increased, Young's modulus and fracture strength of the composites increased from 1831 to 14 MPa to 3049 and 19 MPa, in contrast to P(3HB)/WF, where the values decreased by a factor of 1.5–2.0. The half-life of composites with BNC and WF in soil was 180 and 220 days, respectively. Changes in the structure of the microbial community were determined as depending on the filler type; primary destructors among bacteria and fungi were isolated and identified. Environmentally friendly and completely degradable composites show promise as cellulose-plastic materials for practical application. [ABSTRACT FROM AUTHOR]

Fused deposition molding (FDM) is a commonly used 3D printing method, and polylactic acid (PLA) has become one of the most important raw materials for this technology due to its excellent warping resistance. However, its mechanical properties are insufficient. Polybutylene adipate terephthalate (PBAT) is characterized by high toughness and low rigidity, which can complement the performance of PLA. The biodegradable polymers produced by blending the two have thus been used to replace petroleum-based plastics in recent years, but the high cost of the blends has limited their wide applications. Introducing plant fibers into the blends can not only maintain biodegradability and improve the overall performance of the plastics but also reduce their costs greatly. In this study, the PBAT/PLA blends with a mass ratio of 70/30 were selected and mixed with wood flour (WF) to prepare ternary composites using a FDM 3D printing technique. The effects of WF dosage on the mechanical properties, thermal properties, surface wettability, and melt flowability of the composites were investigated. The results showed that the proper amount of WF could improve the tensile and flexural moduli of the composites, as well as the crystallinity and hydrophobicity of the printed specimens increased with the content of WF, while the melt flow rate decreased gradually. Compared to PBAT/PLA blends, WF/PBAT/PLA composites are less costly, and the composite containing 20 wt.% WF has the best comprehensive performance, showing great potential as raw material for FDM 3D printing. [ABSTRACT FROM AUTHOR]

This work studied biocomposites based on a blend of low-density polyethylene (LDPE) and the ethylene–vinyl acetate copolymer (EVA), filled with 30 wt.% of cellulosic components (microcrystalline cellulose or wood flour). The LDPE/EVA ratio varied from 0 to 100%. It was shown that the addition of EVA to LDPE increased the elasticity of biocomposites. The elongation at break for filled biocomposites increased from 9% to 317% for microcrystalline cellulose and from 9% to 120% for wood flour (with an increase in the EVA content in the matrix from 0 to 50%). The biodegradability of biocomposites was assessed both in laboratory conditions and in open landfill conditions. The EVA content in the matrix also affects the rate of the biodegradation of biocomposites, with an increase in the proportion of the copolymer in the polymer matrix corresponding to increased rates of biodegradation. Biodegradation was confirmed gravimetrically by weight loss, an X-ray diffraction analysis, and the change in color of the samples after exposition in soil media. The prepared biocomposites have a high potential for implementation due to the optimal combination of consumer properties. [ABSTRACT FROM AUTHOR]

The problem of wastewater pollution in the production of monosodium glutamate (MSG) is becoming more and more serious. A novel type of chemically modified Salix psammophila powder charcoal (SPPCAM) was synthesized to address the chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) in MSG wastewater. SPPCAM was prepared by carbonization method, in which inorganic ammonium molybdate (AM) was used as modifier and Salix psammophila powder (SPP) was used as raw material. Under optimal treatment conditions, maximum removal rates (removal capacities) of 45.9% (3313.2 mg·L−1) for COD and 29.4% (23.2 mg·L−1) for NH3-N in MSG wastewater were achieved. The treatment results significantly outperforming the unmodified Salix psammophila powder charcoal (SPPC), which only achieved removal rates (removal capacities) of 10.6% (763.9 mg·L−1) for COD and 12.9% (10 mg·L−1) for NH3-N. SPPC and SPPCAM before and after preparation were analysed by FT-IR and XRD, and Mo ions in the form of Mo2C within SPPCAM were successfully loaded. SEM, EDS-Mapping, BET, and other methods were used to analyse SPPCAM before and after MSG wastewater treatment, demonstrating that SPPCAM effectively treated organic pollutants in monosodium glutamate wastewater. The NH3-N in the treated MSG wastewater has reached the standard of safe discharge. [ABSTRACT FROM AUTHOR]

In this work, a new compatibilizer, ternary monomer grafted polypropylene (hereafter shorted as: G‐PP), was successfully synthesized by solid phase grafting of maleic anhydride, methyl methacrylate, and butyl‐acrylate onto polypropylene. For all developed polypropylene matrix composites, the prepared G‐PP evidently showed enhancing mechanical properties on PP/wood flour (WF) composites, which is obviously superior to those from maleic anhydride grafted polypropylene (W‐PP) and virgin polypropylene (C‐PP). In particular, the wettability of G‐PP was greatly improved, while the melting temperature and β crystal phase amounts of the WF composites with G‐PP are much higher when compared to that of W‐PP and C‐PP. This can be reasonably explained by the formation of continuous micropores and filaments in WF composites containing G‐PP, as verified by hot stage polarizing optical microscope (POM). Meanwhile, the G‐PP effectively reduced movement of molecular chains of WPC and formed a better interface layer with WF, which contributed to penetrate more deeply and form micro‐crosslinking in the WF layer. We believe that the results reported in this work will increase the added value of polypropylene based wood plastics composites (WPC) and allow WPC to participate in lightweight and environmentally friendly products. [ABSTRACT FROM AUTHOR]

A novel elastomer-modified multicomponent, multiphase waste-sourced biocomposites, was prepared for converting waste biomass and plastic into value-added products. The effects of blending elastomer–olefin block copolymer (OBC) and maleic anhydride (MAH), and divinylbenzene (DVB) co-grafting of recycled polypropylene (rPP) matrix on the adhesion interface, structure, and properties of high wood flour-filled (60 wt.%) composites were thoroughly investigated. The results indicated that DVB introduced branched structures into the polymer matrix molecular chain and increased the MAH grafting rate. Co-grafting rPP/OBC blends enhanced the interfacial adhesion among rPP, OBC, and wood flour. Additionally, MAH-grafted OBC was prone to encapsulating rigid wood flour, thereby forming an embedded structure. Notably, the tensile modulus and impact strength of the final three-component composites increased by 60% and 125%, respectively, compared with the unmodified composites. Additionally, dynamic mechanical analysis revealed that DVB-induced branching promoted the formation of microvoids in the OBC shell layer surrounding the wood, which in turn induced significant plastic deformation in the polymer matrix. This work offers a facile and efficient method for preparing high-toughness, high-stiffness, and low-cost waste PP-based composites for automotive interiors, and indoor and outdoor decoration. [ABSTRACT FROM AUTHOR]

This study aims to develop a recyclable, economical, and flame-retardant composite material using polypropylene, beech flour, tetrabromobisphenol A bis (TBBPA), and antimony trioxide (ATO). Flame-retardant additives (TBBPA and ATO) were initially added into polypropylene at different rates, and masterbatch (MB) samples were produced by the extrusion method. Subsequently, different percentages of wood flour (10%, 15%, 20%, 25%, and 30%) along with 60% MB were added to the polypropylene to create wood–polymer composites (WPC) using the injection method. The TBBPA, ATO, and wood flour were introduced through side-feeding hoppers during injection to ensure a homogeneous distribution within the WPC. Physical, thermal, and mechanical tests were conducted on the WPC samples. Additionally, TGA, FTIR, and SEM analyses were performed. The results indicated that the optimal ratios for TBBPA and ATO additives were 20% and 10%, respectively. It was observed that increasing the wood flour content in the WPC samples led to enhanced density, water absorption, hardness, impact, and abrasion resistance. Conversely, MFI, bending strength, and tensile strength decreased with higher wood flour content. It was observed that WPC samples exhibited flame resistance up to 725 °C. The produced WPC materials can be used in flooring applications, interior furniture, decorative wall panels, and aesthetic structural elements due to their fire behavior, good mechanical properties, low water-absorption rates, and aesthetic appearance. [ABSTRACT FROM AUTHOR]

In this work, two binary carbon-based composite phase change materials consisting of paraffin (PW), lauric acid (LA) and tetradecanol (TD) were prepared. Delignified wood flour (DWF) was obtained through treatment with a mixture of NaOH and Na2SO3. The pore volumes of DWF and wood flour (WF) are 0.01049 and 0.008955 cm3/g, respectively, and the pore volume of DWF increased by 17.16%. The adsorption capacity of DWF for LA-PW and LA-TD reaches 50%, which is 10% higher than the adsorption capacity of WF for LA-PW and LA-TD. The thermal conductivities of LA-PW/DWF and LA-TD/DWF are 0.3762 and 0.3580 W/m k, respectively. The phase transition temperatures of LA-PW/DWF and LA-TD/DWF are 40.86 ℃ and 19.68 ℃, respectively. The phase transition latent heat for LA-PW/DWF and LA-TD/DWF is 88.86 J/g and 62.31 J/g, which are 33.61% and 26.18% higher than those of LA-PW/WF and LA-TD/WF, respectively. After 200 cycles, the maximum value of the change rate in phase transition temperature for LA-PW/DWF and LA-TD/DWF is less than 2.64%, and the peak shape remains consistent before and after the cycle, which have good thermal stability. The adsorption capacity of DWF obtained by alkali delignification of wood flour was enhanced. LA-PW and LA-TD were uniformly adsorbed in the pore structure of DWF by capillary force and surface tension. LA-PW/DWF and LA-TD/DWF have high phase transition latent heat and good thermal and stability. [ABSTRACT FROM AUTHOR]

Effects of thermoplastic polyurethane (TPU) types (Recycled (R) and Virgin (V)) composites with 15 wt% and 30 wt% oakwood flour addition were studied. Selected physical, mechanical, morphological, and thermal properties of resulting polymer composites were analyzed. Test samples were manufactured using injection molding, except that abrasion resistance specimens were manufactured using a compression molding process. The findings indicated that the types of TPU and filler contents played a significant role in the density and mechanical properties of the TPU test samples. The increased oak wood flour contents in both TPU types showed improvement in density, tensile modulus, hardness, flexural strength flexural modulus, dynamic impact strength, and yield strength of the composite while decreasing the elongation at break values. In addition, both TPU types and filler contents significantly affected the densities of VTPU and R-TPU. The TPUs type, filler content, and cycle-rpm affected Taber's abrasion resistance values. Weight loss, which increased with the number of cycles for the control samples, decreased with increasing wood flour content. This study aimed to provide an overview of the effect of the wood flour content in the manufacturing of thermoplastic-reinforced composites and to provide a basis for further research and development efforts. [ABSTRACT FROM AUTHOR]

The Northwestern Federal District is a region of Russia rich in a variety of wood species. The properties of wood in this region differ significantly from the properties of wood grown in other countries or in the eastern part of Russia, which leads to differences in energy costs of grinding wood. The aim of this research has been to estimate the specific energy costs of grinding wood to the state of wood flour, which will be used as the basis for wood polymer composite consumables in additive technologies. Wood flour has been obtained by grinding wood in a laboratory disk mill, repeatedly reducing the particle size. The granulometric composition has been analyzed for beech, oak, larch, alder and pine wood at 1, 3, 5 and 10 grinding cycles. Particle sizes have been determined by analyzing images obtained using an optical microscope and processed in the ImageJ graphic program. The specific energy costs of grinding have been estimated by recording the power with a wattmeter every second with repeated feeding of wood flour for the known mill productivity. When calculating the specific energy consumption, the moisture content of each wood species has been taken into account, as well as productivity losses associated with the adhesion of wood particles to the working surfaces of the dispersing set and the inner area of the disk mill body. The research has revealed a relationship between the specific energy costs and the particle size of wood flour obtained from various wood species. Regression analysis of curves corresponding to different wood species has made it possible to obtain exponential and power-law dependencies that do not contradict the fundamental theoretical laws of grinding solid particles. Based on these results, pine wood flour has been recognized as the most energy-efficient option. The established dependencies can be used to predict the specific energy consumption for grinding beech, oak, larch, alder and pine wood in disk mills.

The demand for composite materials is growing every year. In this regard, the competitiveness of a particular product is determined primarily by the price-quality ratio. The most rational option for the production of wood-filled composites is using the materials with the increased performance characteristics. To date, it is the performance characteristics of modern composite materials that are the most significant, not only for final consumers, but also for manufacturers. In this regard, to improve performance characteristics in the production of wood-filled composites, various methods of pre-treatment of wood are used – thermal modification, acetylation, furfulation, ultra-high-frequency processing, alkali treatment, the use of various additives, etc. A promising way to improve the physical and mechanical properties of wood-filled materials is acetylation, whose mechanism consists in the formation of acetyl groups in wood during processing. To reduce production costs and the cost of the final product, it is possible to use a cheaper precursor (for example, icy acetic acid instead of acetic anhydride) with the possibility of intensifying the impregnation process. This article presents the results of obtaining wood-filled composites based on acetylated birch wood flour with its various proportions in the composition. The effect of introducing acetylated wood filler into the composition on the performance properties of composites (abradability, frost-resistance, flexural strength) has been evaluated in comparison with control samples made from untreated birch wood flour. The effect of acetylation with glacial acetic acid on the structure of birch wood flour has been characterized using Fourier-transform infrared spectroscopy. The IR-spectra of the control and acetylated samples contain absorption bands belonging to the corresponding groups of cellulose and lignin of hardwoods. The abradability and frost-resistance coefficients for a wood-filled composite based on acetylated birch wood flour are on average 1.5–2 times lower for all compositions compared to control samples. The results of the research allow us to conclude that acetylation of wood flour as a method of pre-treatment of the filler in order to improve the performance characteristics of the final product is promising for implementation in the production of wood-filled materials.

This research work covered the comparative effect of wood flour (saw dust) and granulated rice husk on the thermal insulation of termite hill clay. The raw clay samples were mined from the Federal University of Technology Akure Campus and processed. Likewise, the saw dust and rice husk were also processed and grinded. The clay samples and the additives were sieved to obtain 300 microns and were mixed in predetermined proportions of 0, 2, 4, 6, 8 and 10 wt. %. Cylindrical samples were developed from the mixtures which were compacted and then air dried before oven dried and finally fired. The fired samples were subjected to selected tests to determine their insulation and refractory properties. These tests include porosity, linear shrinkage, volumetric shrinkage, bulk density, thermal conductivity, thermal shock resistance and cold crushing tests. It was discovered that the saw dust samples meet the ASTM standard for insulating bricks while the rice husk samples did not. Saw dust samples with 2 and 8 wt. % were ones with optimum properties. [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils (CNFs) have theoretically ideal properties for bio-based composite applications; however, the incorporation of these materials into polymers is made challenging by the strong binding of water to CNFs and the irreversible agglomeration of CNFs during drying. Previous methods used "contact dewatering", wherein the addition of wood flour (WF) to CNFs facilitated the mechanical removal of water from the system via cold pressing, which showed potential in producing dried CNF fibrils attached to wood fibers for biocomposite applications. In this work, the viability of contact dewatering with poly(lactic) acid (PLA) powder for PLA/CNF composites was evaluated. The energy efficiency of dewatering, preservation of nanoscale CNF morphology, and mechanical properties were examined by mixing wet CNFs with pulverized PLA at various loading levels, pressing water out of the system, and compression molding and shear mixing composites for testing. The most impressive results from this dewatering method were the preservation of micron-to-nanoscale fibers with high aspect ratios in PLA-CNF composites; increased strength and modulus of 1.7% and 4.2%, respectively, compared to neat PLA; equivalent or better properties than spray-dried nanocellulose at similar loading levels; and an 11-194x reduction in drying energy compared to spray-drying CNFs. [ABSTRACT FROM AUTHOR]

The objective of the present work was to explore the effects of accelerated weathering test on properties of poly(lactic acid) (PLA)/poly(butylene adipate- co -terephthalate) (PBAT) blend and PLA)/PBAT/wood flour (WF)/wollastonite (WT) composite. The 70/30 (wt%/wt%) PLA/PBAT blend and its composite with 25 phr WF and 5 phr WT were prepared on a twin screw extruder and injection molding machine. Resulted blend and hybrid composite were exposed to accelerated weathering conditions of UV-irradiation and moisture cycles at 63°C in a laboratory Xenon Weather-Ometer chamber for various periods (250, 500, 750, and 1000 h). The alterations in the surface quality (color change), chemical structure, surface morphology, tensile properties, thermal behaviors, and thermal stability of the specimens were evaluated by spectrocolorimetry, Fourier-transform infrared spectroscopy, scanning electron microscopy (SEM), universal testing machine, differential scanning calorimetry and thermogravimetric analysis, respectively. The photo- and hydrolytic degradations were found to occur during the weathering exposure time. Both blend and composite showed a continuous increase in the total color change with prolonged exposure time, which was mainly due to the degradation of PLA and wood components, especially lignin. The SEM images also confirmed their degradations by illustrating roughness, voids, and cavities on the specimen surfaces after accelerated weathering. Meanwhile, the tensile and thermal properties of both blend and composite were found to decrease. Thus, this study can be used for quality control and material certification. [ABSTRACT FROM AUTHOR]

The paper presents the results of testing the properties of wood–polymer composites (WPC) based on plasticised poly(vinyl chloride) (PVC-P). Materials with variable contents of wood filler (Arbocel C 320) or plasticiser (di-isononyl phthalate) were produced and then analysed. The share of wood flour in the material was up to 50 phr, and the plasticiser content was up to 40 phr. Functional properties, such as tensile properties, mechanical properties at variable temperature (DMTA), and water absorption, as well as processing properties such as rheological properties and analysis of the fusion process, were analysed. The influences of wood flour and plasticiser on the composites' properties in the solid and melted state were found. For example, with 40 phr of plasticiser, increasing the filler share from 0 phr to 50 phr resulted in an increased tensile modulus from 18 MPa to 274 MPa and viscosity at a share rate of 20 s−1, from 721 Pa·s to 1581 Pa·s. However, increasing the share of plasticiser from 20 phr to 40 phr with 30 phr of filler reduces the value of these properties from 1760 MPa to 112 MPa and from 2768 Pa·s to 1151 Pa·s, respectively. It was also found that increasing the share of wood flour in the composite noticeably reduces the effectiveness of the plasticiser. [ABSTRACT FROM AUTHOR]

The effect of plant-based fillers on thermal resistance in highly filled biocomposites based on ethylene–vinyl acetate copolymer (EVA) was studied. Wood flour and microcrystalline cellulose were used as fillers. It was shown that the introduction of microcrystalline cellulose into EVA did not affect the thermal stability of the polymer matrix. In contrast, the introduction of wood flour into EVA led to a significant increase in the thermal stability of the entire biocomposite. Oxidation induction time increased from 0 (pure EVA) to 73 min (EVA + wood flour biocomposites). The low-molecular weight phenolic compounds contained in wood flour are likely able to diffuse into the polymer matrix, exerting a stabilizing effect. The discovered stabilizing effect is a positive development for expanding the possibilities of technological processing of biocomposites, including multiple processing. [ABSTRACT FROM AUTHOR]

Intending to minimize the cost of production of pipes intended for construction and building activities and waste recycling, this research studies the physical and mechanical characteristics of high-performance polypropylene random (PPR), a new material extracted from a homopolymer polypropylene. The PPR was filled with untreated and treated wood flour (WF) particles at various content levels 10, 20, 30, and 40 wt.%. The density, melt flow rate, tensile strength, tensile strain, modulus of elasticity, and hardness are used to evaluate the quality of the material. The hydrophobic character of WF resulted from degradation in the physical and mechanical properties. The results showed that the density, the modulus of elasticity, and the hardness increased with the percentage of treated wood flour (TWF). As the percentage of WF increased, the melt flow rate decreased. The tensile strength and strain increased to 27.7 MPa and 543.25%, respectively at 20 wt.% of WF, with 14.8% and 6.65% reached gains compared to the untreated wood flour composites (UWFC) (24.04 MPa and 495.6%). The enhancement of the mechanical properties is thanks to the formed strong links between the particles of WF and the PPR after the thermal and alkaline treatment with sodium hydroxide (NaOH). The removal of hydroxyl groups in the TWF enhances the interfacial bonding between the filler and the PP matrix in the resulting composites. When WF is treated, it is well dispersed; and facilitates the transfer of stress from the matrix to the fillers. The optimum percentage of WF to add into the inner layer of PPR pipes is at a composition of the filler of 20 wt.%. [ABSTRACT FROM AUTHOR]

The conducted study was focused on the development of a new type of technical blend reinforced with natural fillers. The study was divided into two parts, where, in the first stage of the research, unmodified POM was reinforced with different types of natural fillers: cellulose, wood flour, and husk particles. In order to select the type of filler intended for further modification, the mechanical characteristics were assessed. The 20% wood flour (WF) filler system was selected as the reinforcement. The second stage of research involved the use of a combination of polyoxymethylene POM and poly(lactic acid) PLA. The POM/PLA blend (ratio 50/50%) was modified with an elastomeric compound (EBA) and chain extender as the compatibilized reactive (CE). The microscopic analysis revealed that for the POM/PLA system, the filler–matrix interface is characterized by better wettability, which might suggest higher adhesion. The mechanical performance revealed that for POM/PLA-based composites, the properties were very close to the results for POM-WF composites; however, there is still a significant difference in thermal resistance in favor of POM-based materials. The increase in thermomechanical properties for POM/PLA composites occurs after heat treatment. The increasing crystallinity of the PLA phase allows for a significant increase in the heat deflection temperature (HDT), even above 125 °C. [ABSTRACT FROM AUTHOR]

The effects of heat treatment on Cupressus funebris Endl. wood were examined under different combinations of temperature, time, and pressure. The chemical composition, crystallinity, and microstructure of heat-treated wood flour and specimens were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Vacuum heat treatment led to changes in the functional groups and microstructure of C. funebris wood, and the relative lignin content decreased with increasing treatment temperature, which was significant at lower negative pressures. Cellulose crystallinity showed a change rule of first increasing and then decreasing throughout the heat treatment range, and the relative crystallinity ranged from 102.46% to 116.39%. The cellulose treated at 120 °C for 5 h at 0.02 MPa had the highest crystallinity of 44.65%. These results indicate that although heat treatment can improve cellulose crystallinity, very high temperatures can lead to decreased crystallinity. The morphology and structure of the cell wall remained stable throughout the heat treatment range; however, at elevated temperatures, slight deformation occurred, along with rupture of the intercellular layer. [ABSTRACT FROM AUTHOR]

Wood plastic composites (WPC) were prepared using KH-570 modified wood flour and polypropylene (PP), and the mechanical properties and aging resistance of WPC were studied. The results show that when the wood flour content is 30%, WPC with the best comprehensive properties such as mechanical properties and aging resistance can be prepared. At this time, the tensile strength and bending strength of WPC reaches their maximum values, which are 5.2% and 56.5% higher than pure PP, respectively. The tensile strength and bending strength of WPC after UV aging are 2.7% and 20.6% higher than pure PP plastic, respectively. WPC has the highest tensile strength and bending strength after water resistance, which are 3.0% and 18.8% higher than pure PP plastic, respectively. The Vicat softening temperature of WPC reaches its maximum value, which is 10 °C higher than that of pure PP plastic. The quality loss rate after mold corrosion resistance is 0.82%. [ABSTRACT FROM AUTHOR]

The aim of the present study is to use beech wood flour (WF) and expanded ethylene vinyl acetate (EVA) copolymer industrial waste to develop a sustainable composite and its production method for further engineering use. Polyamide (PA) powder waste obtained after multiple selective laser sintering (SLS) thermal cycles was used to increase the strength and adhesion between the waste composite components. The morphological, mechanical, and thermal properties of the EVA/WF composites were characterised along with their interfacial wetting and water absorption properties. Optical and electron microscopy investigations revealed that the composites prepared have homogeneous dispersion and good interfacial adhesion between EVA and wood. The addition of SLS waste PA powder increases the strength and stiffness of the composite developed. The composite with 40 wt% WF exhibited the best water absorption, mechanical properties, and processability among the various compositions. The sustainable composite proposed can replace commercially available materials, which helps to save resources and reduce waste. [ABSTRACT FROM AUTHOR]

Wood‐plastic composites are green composites made of plastic as the matrix and wood as the filler; however, the incompatibility between these two leads to the degradation of the composites. This paper reports the synthesis of a novel bio‐based compatibilizer, annotated as OA‐g‐H20, by grafting oleic acid (OA) on a hyperbranched polyester (Boltorn H20). The effect of modifying recycled polypropylene‐based wood–plastic composites with this compatibilizer was then assessed. The Fourier transform infrared spectroscopy, thermogravimetric analysis, and gel permeation chromatography techniques were employed to characterize the fabricated OA‐g‐H20, while its modification effect was assessed by differential scanning calorimetry, dynamic thermomechanical analysis, scanning electron microscopy, and mechanical property tests. The experimental results revealed that the optimal addition amount of OA‐g‐H20 was 2.0 wt.%. Highlights: A new bio‐based compatibilizer, OA‐g‐H20, for wood–plastic composites is reported.OA‐g‐H20 was obtained by grafting oleic acid on a hyperbranched polyester (H20).OA‐g‐H20 provided good mechanical reinforcement for the wood–plastic composites.OA‐g‐H20 improved the crystallinity of the composites.The reinforcement mechanism of OA‐g‐H20 in wood–plastic composites is elucidated. [ABSTRACT FROM AUTHOR]

Abstract Mechanical properties of wood–plastic composites are influenced by a particle size and surface morphology of wood flour. Generally various sizes of wood flour are produced from single solid wood even if the single process is used. If the different particle size of wood flour is produced from different wood tissue such as earlywood (EW) and latewood (LW), not only particle size but also density and chemical composition of wood flour might influence the mechanical property of final products. This study aims to investigate the relationship between particle size and their origin; EW and LW. EW and LW were separately milled to produce the EW and LW flour by dry and wet milling. Hyperspectral images ranging 400–1000 nm for each wood flour were used as training data. Discriminant model of EW and LW flour developed by PLS-DA showed over 0.77 of accuracy. Then the EW and LW were dry and wet milled together and screened by three different sieve openings to obtain different particle size wood flour. Discriminant model was applied for the hyperspectral images of each size of wood flour to estimate the EW and LW ratio. The result showed that increasing sieve opening resulted in the increasing ratio of LW for dry milled wood flours. The results suggest that the EW was easily pulverized than LW.

This study involved the optimization of the molded pieces manufacturing process from a poly-3-hydroxybutyrate-co-3-hydroxyvalerate biocomposite containing 30% wood flour by mass. The amount of wood flour and preliminary processing parameters were determined on the basis of preliminary tests. The aim of the optimization was to find the configuration of important parameters of the injection process to obtain molded pieces of good quality, in terms of aesthetics, dimensions, and mechanical properties. The products tested for quality were dog bone specimens. The biocomposite was produced using a single-screw extruder, whereas molded pieces were made using an injection molding process. The Taguchi method was applied to optimize the injection molding parameters, which determine the products quality. Control factors were selected at three levels. The L27 orthogonal plan was used. For each set of input parameters from this plan, four processing tests were performed. The sample weight, shrinkage, elongation at break, tensile strength, and Young's modulus were selected to assess the quality of the molded parts. As a result of the research, the processing parameters of the tested biocomposite were determined, enabling the production of good-quality molded pieces. No common parameter configuration was found for different optimization criteria. Further research should focus on finding a different range of technological parameters. At the same time, it was found that the range of processing parameters of the produced biocomposite, especially processing temperature, made it possible to use it in the Wood Polymer Composites segment. [ABSTRACT FROM AUTHOR]

The work presents the results of a comprehensive study on obtaining compositions based on polypropylene and natural fillers modified by enzymatic preparations under high-shear forces. The experiment protocol includes determining the modification time and the ratio of water volume to the mass of natural filler (hydro modulus) during modification, which turned out to be different for each type of filler. Physical and mechanical analyses were conducted to evaluate the operational characteristics of the obtained composites, with particular attention given to comparing the modified compositions with their unmodified counterparts. The time and hydro module of the enzymatic modification of the natural fillers under consideration were investigated, which turned out to be different for each type of filler. It was found that surface modification of natural fillers improves mechanical properties; namely, the tensile strength of composites with wood and sunflower fillers increases by 10%, and the impact viscosity of composites also increases by 12% with wood and sunflower fillers. Water absorption decreases in composites, after 2 h boiling, with wood flour by 30% and with rice husk by 10%. After a 14-day test at room temperature, water absorption decreases by more than 30% in composites with rice husk. When determining the free surface energy of composites, it was found that the modification of the filler reduces the polarity of the composites in all samples, which can be interpreted as an improvement in the interaction between the filler and the polymer matrix. The findings of this research have important implications for the development of advanced polymeric materials that can be used in a wide range of applications, including automotive, aerospace, and construction industries. The results underscore the importance of surface modifications to optimize the properties of polymeric composites and provide valuable insights into the role of natural fillers in enhancing the performance of these materials. [ABSTRACT FROM AUTHOR]

This article summarizes findings in the field of the history, composition, and mechanical properties of WPCs (wood–plastic composites) formed by combining two homogeneous substances, i.e., a polymer matrix with cellulose fibers in a certain ratio (with the addition of additives). In relation to a wide range of applied natural reinforcements in composites, it focuses on wood as a fundamental representative of lignocellulosic fibers. It elucidates the concept of wood flour, the criteria for its selection, methods of storage, morphological characteristics, and similar aspects. The presence of wood in the plastic matrix reduces the material cost while increasing the stiffness. Matrix selection is influenced by the processing temperature (Tmax = 200 °C) due to the susceptibility of cellulose fibers to thermal degradation. Thermoplastics and selected biodegradable polymers can be applied as matrices. The article also includes information on applied additives such as coupling agents, lubricants, biocides, UV stabilizers, pigments, etc., and the mechanical/utility properties of WPC materials. The most common application of WPCs is in automotive sector, construction, aerospace, and structural applications. The potential biodegradability and lower cost of applications featuring composite materials with natural reinforcements motivated us to delve into this type of work. [ABSTRACT FROM AUTHOR]

Pretreatment serves as an important step in maximizing the efficient utilization of woody biomass feedstock. This study focused on enhancing the component and structural properties of apple wood to optimize the utilization of apple wood resources effectively. This study presents the optimization of, the apple wood pretreatment system, combining bioenzyme and hydrothermal treatments. This study aimed to investigate the effect of different bioenzyme pretreatment conditions on the components and structural properties of apple wood extract and to analyze the feasibility of enzyme solution reuse. Fourier transform infrared spectroscopy analysis revealed an increase in cellulose content in the wood flour following enzyme treatment. Concurrently, changes in characteristic peaks indicated an increased hemicellulose content and a reduction in lignin content after the pretreatment, correlating with fraction analysis results. Scanning electron microscopy illustrated that the dense structure of the fiber surface was disrupted after treatment. Notably, the results indicated that the recovered biocomposite enzymes exhibited excellent activity, suggesting their potential for reuse. [ABSTRACT FROM AUTHOR]

Background and aim: As a result of population growth, paper and wood products consumption has increased, and restrictions on using forest wood raw materials initiated the utilization poplar trees as fast-growing spices. The aim of this study was to focus on identification and comparison of the phenolic chemical components in poplar woods (populous nigra and populous deltoides). Materials and methods: In this study, three trees from each poplar tree were randomly felled in plantation near Nowshar, Iran. Then three discs were cut from each log. At first, wood was grounded and then wood flour extractive were measured using TAPPI standard procedure. Wood flour was extracted by acetone and extractives residue was added to BSTFA reactor and samples were kept in constant temperature bath at 70oC for an hour. The extractive samples were then analyzed by GC/MS. The compounds were identified using GC diagram which shows abundance and retention time of each compound, and calculation of quartz index and Adams table. Results: The result of GC-MS showed that there exist 68 and 105 compounds in wood of Populus nigra and Populus detoides, respectively. di-Limonene (30.26%), bis (2-ethylhexyl) phthalate (10.07%), Gamma-Sitosterol (1.06%), Hexadecanoic acid (2.0%), gamma-Terpinene (4.02%) and 4-Hydroxy-Benzoic acid (3.62%) were the most important compounds in wood of Populus detoides. There were the Limonene (25.62%), Anymol (5.29%), gamma-Terpinene (3.38%), 1, 2-Benzandicarboxylic acid (2.00%) and bis (2-ethylhexyl) phthalate (0.68%) as the most important compounds in wood of Populus nigra. Conclusion: The gas chromatographs showed that Limonene, Benzene methanol, alpha-Terpineol, beta-Bisabolene, Hexadecanoic acid and bis (2-ethylhexyl) phthalate were the 7 common compounds in the wood of Populus nigra and Populus deltoides. These compounds can play an important role in the durability and consumption of these woods. [ABSTRACT FROM AUTHOR]

Mechanical properties of wood–plastic composites are influenced by a particle size and surface morphology of wood flour. Generally various sizes of wood flour are produced from single solid wood even if the single process is used. If the different particle size of wood flour is produced from different wood tissue such as earlywood (EW) and latewood (LW), not only particle size but also density and chemical composition of wood flour might influence the mechanical property of final products. This study aims to investigate the relationship between particle size and their origin; EW and LW. EW and LW were separately milled to produce the EW and LW flour by dry and wet milling. Hyperspectral images ranging 400–1000 nm for each wood flour were used as training data. Discriminant model of EW and LW flour developed by PLS-DA showed over 0.77 of accuracy. Then the EW and LW were dry and wet milled together and screened by three different sieve openings to obtain different particle size wood flour. Discriminant model was applied for the hyperspectral images of each size of wood flour to estimate the EW and LW ratio. The result showed that increasing sieve opening resulted in the increasing ratio of LW for dry milled wood flours. The results suggest that the EW was easily pulverized than LW. [ABSTRACT FROM AUTHOR]

The fabrication of lignocellulose-based hydrogels typically involves complex modification or dissolution processes using a single component of lignocellulose. However, these processes often have a significant environmental impact, posing challenges to achieving green production of these hydrogels. In this study, we present a non-dissolving strategy to convert whole components of corn stover directly into hydrogel. The central step in this strategy is to expose more functional groups in the corn stover through steam explosion. The exposure of functional groups allowed the steam-exploded corn stover to strengthen the mechanical properties of poly(vinyl alcohol) (PVA) hydrogel by forming more hydrogen bonds with PVA molecules. The tensile strength of the prepared lignocellulose-based hydrogel reached 329.75 kPa, which was 432.69% higher compared to the pure PVA hydrogel. Furthermore, this hydrogel exhibited the advantageous properties of lignin, such as antioxidant and UV resistance capabilities, and was shown to be useful as a sand-fixing agent for large-scale applications. Finally, we verified the universal applicability of the non-solubilizing strategy by preparing similarly shaped hydrogel products from wheat bran and poplar wood flour as well. In summary, our non-dissolving strategy provides a simpler and more cost-effective method than the intricate process of creating lignocellulose-based hydrogels. This simplification helps convert abundant lignocellulosic materials into valuable products. [ABSTRACT FROM AUTHOR]

It is easier and cheaper to prevent forest fires than to extinguish them, therefore, the development of long-lasting and environmentally friendly fire-retarding materials is highly desirable to prevent the spread of forest fires. In this study, soluble carboxymethyl starch replaced insoluble carboxymethyl cellulose to improve the compressive strength of inorganic gel and overcome the weakness of fragility. When the concentration of polymer carboxymethyl starch and crosslinking agent aluminum citrate were 0.5% and 0.3%, respectively, the inorganic/organic composite gel showed the best comprehensive performance (including gelation time, water retention, seepage velocity and strength). Additionally, the antioxidant tannin was introduced into the inorganic/organic gel, which effectively inhibited the oxidation of wood flour, making its inhibition rate reached 23.1%, about twice that of pure inorganic gel. This is mainly attributed to the ability of tannin to inhibit the oxidation process of active groups, including carbon-oxygen, hydroxyl, and methyl of the wood powder, thereby enhancing the flame resistance of the composite gel. Probable mechanism of forest fire suppression by the antioxidant composite gel is proposed, which involves oxygen isolation, evaporative cooling, and chain reaction inhibition. [ABSTRACT FROM AUTHOR]

Wood–plastic composites (WPCs), abbreviated as WPCs, are typically composite materials made by mixing wood flour and thermoplastic resins, and then shaped through processes such as extrusion or compression. They have emerged as a viable and advanced alternative to traditional wood and plastic materials, offering an amalgamation of the best properties of both. This study utilized discarded milk bottles as the polymer matrix (mainly composed of high-density polyethylene, HDPE) and added wood flour, recycled protective clothing (Tyvek®), and diatomite recycled from brewery waste as reinforcement. Additionally, pre-treated aluminum hydroxide powder from waste artificial marble was added. The results indicated that the optimal processing temperature for the WPCs was 175 °C. The mechanical properties of the material increased with the addition of recycled protective clothing and pre-treated aluminum hydroxide powder. The increase in tensile strength can reach up to 28%. The thermal conductivity of the WPCs also significantly increased with the addition of pre-treated aluminum hydroxide powder. Furthermore, sunlight analysis showed that the surface temperature of the WPCs decreased by approximately 8.5 °C, which corresponds to a reduction of 13% after adding pre-treated aluminum hydroxide powder. Therefore, they can be applied to outdoor cool WPCs to reduce the risk of foot burns or used as roof heat-insulating layers to reduce indoor air conditioning usage, achieving energy-saving and carbon reduction. This study demonstrates that high-performance and high-value green plastics made from various recycled materials can contribute to the goals of a circular economy and sustainable carbon reduction. [ABSTRACT FROM AUTHOR]

CQDs are a type of fluorescent nanocarbon material that possess excellent optical properties. They have a wide range of raw material sources, making them a versatile option for various applications. The use of fluorescent materials to enhance the solar energy capture capacity of chloroplasts has the potential to significantly improve natural photosynthesis. CQDs and N-CQDs were prepared from natural Salix wood powder using a simple, green, and environmentally friendly hydrothermal method. These materials can effectively capture ultraviolet (UV) light and were used for photosynthesis to enable chloroplasts to utilize UV light that cannot be absorbed by them. The chlorophyll content of leaves treated with CQDs and N-CQDs increased, with the N-CQDs 25 mg/L treated group showing a 35.6% increase compared to the untreated group. Additionally, the treatment of CQDs and N-CQDs positively affected the transfer of electrons from photosystem II, further enhancing photosynthetic activity. This study presents ideas for expanding the use of solar energy, optimizing the photosynthesis charge transfer pathway, and improving solar energy conversion efficiency. [ABSTRACT FROM AUTHOR]

Fused deposition molding (FDM) is a commonly used 3D printing method, and polylactic acid (PLA) has become one of the most important raw materials for this technology due to its excellent warping resistance. However, its mechanical properties are insufficient. Polybutylene adipate terephthalate (PBAT) is characterized by high toughness and low rigidity, which can complement the performance of PLA. The biodegradable polymers produced by blending the two have thus been used to replace petroleum-based plastics in recent years, but the high cost of the blends has limited their wide applications. Introducing plant fibers into the blends can not only maintain biodegradability and improve the overall performance of the plastics but also reduce their costs greatly. In this study, the PBAT/PLA blends with a mass ratio of 70/30 were selected and mixed with wood flour (WF) to prepare ternary composites using a FDM 3D printing technique. The effects of WF dosage on the mechanical properties, thermal properties, surface wettability, and melt flowability of the composites were investigated. The results showed that the proper amount of WF could improve the tensile and flexural moduli of the composites, as well as the crystallinity and hydrophobicity of the printed specimens increased with the content of WF, while the melt flow rate decreased gradually. Compared to PBAT/PLA blends, WF/PBAT/PLA composites are less costly, and the composite containing 20 wt.% WF has the best comprehensive performance, showing great potential as raw material for FDM 3D printing.

To optimize powder explosive consolidation technology, an improved explosive consolidation device capable of relieving pressure was designed. Bulk nano-aluminum materials achieving more than 98% of standard density were successfully fabricated by explosive consolidation. The effect of different detonation velocities on the properties of the consolidated aluminum was investigated by varying the ratio of the ammonium nitrate explosive (AN-TNT) and wood flour to adjust the detonation velocity. The results revealed that the production of "Mach holes" (defects produced by excess energy in a converging shock wave) can be reduced by decreasing the detonation velocity. At a detonation velocity of 2158 m/s, bulk aluminum with high density, high hardness, high strength, and uniform microstructure without any Mach holes and with a grain size of about 80 nm can be achieved. The hardness of explosively consolidated aluminum was four times that of aluminum prepared by general industrial technology, and its compressive strength double that of industrially prepared aluminum. [ABSTRACT FROM AUTHOR]

The intensive development of the polyurethanes industry and limited resources (also due to the current geopolitical situation) of the raw materials used so far force the search for new solutions to maintain high economic development. Implementing the principles of a circular economy is an approach aimed at reducing the consumption of natural resources in PU production. This is understood as a method of recovery, including recycling, in which waste is processed into PU, and then re-used and placed on the market in the form of finished sustainable products. The effective use of waste is one of the attributes of the modern economy. Around the world, new ways to process or use recycled materials for polyurethane production are investigated. That is why innovative research is so important, in which development may change the existing thinking about the form of waste recovery. The paper presents the possibilities of recycling waste (such as biochar, bagasse, waste lignin, residual algal cellulose, residual pineapple cellulose, walnut shells, silanized walnut shells, basalt waste, eggshells, chicken feathers, turkey feathers, fiber, fly ash, wood flour, buffing dust, thermoplastic elastomers, thermoplastic polyurethane, ground corncake, Tetra Pak®, coffee grounds, pine seed shells, yerba mate, the bark of Western Red Cedar, coconut husk ash, cuttlebone, glass fibers and mussel shell) as additives or fillers in the formulation of polyurethanes, which can partially or completely replace petrochemical raw materials. Numerous examples of waste applications of one-component polyurethanes have been given. A new unexplored niche for the research on waste recycling for the production of two components has been identified. [ABSTRACT FROM AUTHOR]

Rigid polyurethane foams (RPUF) filled with lignocellulosic fillers have gained considerable interest due to their mechanical performance and eco-friendly characteristics. However, their flammability and photodegradation resistance properties still need further improvement, which may be achieved by incorporating various particles. This study investigated the effect of adding 2.5% of wood flour and 5%–15% of an organophilic nanoclay (relative to the wood flour weight) on the RPUF morphology, density, compressive strength, thermal stability, flammability, and photodegradation resistance. The addition of wood flour and nanoclay made the RPUF cells more rounded and disrupted but did not affect density. The compressive properties were adversely impacted. Nevertheless, the nanoclay significantly improved both flammability and photodegradation resistance compared to the neat RPUF. [ABSTRACT FROM AUTHOR]

The effect of expanded vermiculite (e-VMT) was evaluated relative to the physical, mechanical, and flame retardancy performance of flat-pressed wood plastic composites (WPCs). Various contents of e-VMT (2.5, 5, 7.5, 10, 15%) were added instead of wood flour (WF) to the matrix. Due to the hydrophilic nature of the WF, water absorption (WA) and thickness swelling (TS) of WPCs increased as compared to neat polymer-based panels. Meanwhile, e-VMT incorporation limited the WA and TS values. As expected, the lowest WA and TS values were obtained from the highest e-VMT-reinforced WPCs. The addition of e-VMT was also found to enhance the mechanical properties of WPCs. As the e-VMT content increased and the WF content decreased, there was an improvement in flexural strength, modulus of elasticity (MOE), and tensile strength. Compared to the neat polymer panels, the MOE of WPCs increased by up to 77%. Additionally, the flame retardancy performance of WPCs improved with e-VMT reinforcement, with limiting oxygen index (LOI) values increasing up to 24%. Scanning electron microscopy (SEM) images also demonstrated the favorable integration of e-VMT with matrix, thereby improving the mechanical properties. The inconsistency between WF and polymer was also well-observed, highlighting the tendency of WF to interact easily with water. [ABSTRACT FROM AUTHOR]

Developing green composite with high biomass content is one crucial way to realize the strategy of 'carbon reduction'. The type of polyurethane prepolymer and its soft segment's structure have an important influence on the structure and properties of composite materials. This work focused on preparing different kinds of wood powder-polyurethane prepolymer (WCLPU) composite with high biomass content to study the effects of the molecular weight of the soft segment of the polyurethane prepolymer (PCLPU) on the structure and properties of the composites. The results showed that the composite materials with 70 wt% wood content exhibited high strength and good bending performance. Specifically, with decreasing molecular weight of the PCLPU soft segment, the bending strength and bending modulus of the modified WCLPU composite also increased. This work has laid a foundation for studying the effects of the molecular weight of the PCLPU soft segment on the structure and properties of composite materials. [ABSTRACT FROM AUTHOR]

In the modern world, many products are disposable or have a very short lifespan, while at the same time, those products are made from materials that will remain in the environment in the form of waste for hundreds or even thousands of years. It is a serious problem; non-biodegradable polymer wastes are part of environmental pollution and generate microplastics, which accumulate in the organisms of living beings. One of the proposed solutions is biodegradable polymers and their composites. In our work, three types of polylactide-based composites with plant-derived fillers: microcellulose powder, short flax fibers, and wood flour at 2 wt.% were prepared. Poly(lactic acid) (PLA)-based biocomposite properties were characterized in terms of mechanical and surface properties together with microscopic analysis and Fourier-transform infrared spectroscopy (FTIR), before and after a UV (ultraviolet)-light-aging process to determine the effects of each cellulose-based additive on the UV-induced degradation process. This research shows that the addition of a cellulose additive can improve the properties of the material in terms of the UV-aging process, but the form of the chosen cellulose form plays a crucial role in this case. The testing of physicochemical properties demonstrated that not only can mechanical properties be improved, but also the time of degradation under UV light exposure can be controlled by the proper selection of the reinforcing phase and the parameters of the extrusion and injection molding process. The obtained results turned out to be very interesting, not only in terms of the cost reduction of the biocomposites themselves, as mainly the waste from the wood industry was used as a low-cost filler, but also that the additive delays the aging process occurring during UV light exposure. Even a small, 2 wt.% addition of some of the tested forms of cellulose delayed surface degradation, which is one of the most important factors affecting the biodegradation process. [ABSTRACT FROM AUTHOR]

In this study, activated PLA/olive wood flour (OWF) composite films were prepared by a solvent casting process with different wood flour contents (0, 1, 3, 5 and 10 wt%). 3% Cinnamon Essential Oil (CEO) is incorporated into the biocomposite film to impart antimicrobial activity. OWF and CEO properties were examined using FTIR and total phenol quantification. Biocomposite films with and without CEO were tested by FTIR and tensile strength. The antimicrobial activity of biocomposite films was tested against four types of fungi and five types of bacteria. CEO and OWF extracts physically interact with PLA, affecting its mechanical and antimicrobial properties. In addition, only 1% of OWF and CEO achieved better performance. The best antifungal inhibition against A. flavus and F. oxysporum was observed in the case of 10% of OWF, and the best antibacterial activity for P. aeruginosa and S. aureus was observed for OWC0 films. The combined use of OWF and CEO showed synergistic antifungal properties. Overall, low content of OWF and CEO could bring antibacterial and antifungal activities to biocomposite PLA/OWF biofilms with satisfactory mechanical properties. The primary use of these films is cereal packaging applications. [ABSTRACT FROM AUTHOR]

It is anticipated that the creation of wood-polymer composites (WPC) made of naturally renewable polymers and their derivatives (biocomposites) would have a significant practical use due to the rise in prices for synthetic thermoplastic polymers derived from oil and gas. Furthermore, the necessity to replace synthetic polymers such as polyethylene, polypropylene, polyvinyl chloride, and others as components of composite materials is also associated with environmental hazards caused by their low degradation rate in the natural media (soil, water, and air). A further problem for manufacturers of WPC is the legislative requirement for autonomous neutralisation of production waste. One of the potential materials for practical application in the production of WPC are binders based on plasticised cellulose acetates. Russian and foreign scientists have studied the influence of the degree of acetylation of cellulose acetate on the properties of polymeric materials that do not contain lignocellulose fillers. There is no information found concerning the secondary use of cellulose acetate waste for the production of WPC. This article presents the results of an investigation into the hot pressing of biocomposites with a polymer phase of plasticised cellulose acetates of varying degrees of acetylation and fillers: wood flour and waste acetate photographic film. An experimental and statistical dependence of the effect of the degree of acetylation of cellulose acetate and filler content in the biocomposite on its properties was developed, sufficient to exceed a confidence level of 0.9. The experimental specifications included decomposition in activated soil, water absorption, bending strength, Brinell hardness, etc. Some test results showed that the derived biocomposites have the same level of properties as the reference WPC, which consists of a high-density polyethylene phase with a wood flour content of 50 %. The derived dependencies allow us to predict changes in the properties of biocomposites at different degrees of acetylation of plasticised cellulose acetate and filler content. Moreover, they solve the problem of choosing the optimal chemical combination for WPC for manufacturing a specific product by hot pressing. For citation: Shkuro A.E., Glukhikh V.V., Usova K.A., Chirkov D.D., Zakharov P.S., Vurasko A.V. Deriving Biocomposites of Polymer Phase Plasticised Cellulose Acetates with Varying Degrees of Acetylation. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 4, pp. 155–168. (In Russ.). https://doi.org/10.37482/0536-1036-2023-4-155-168