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Wood-polymer composites (WPCs) combine the properties of wood and polymers. Creating composites involves adding plant or wood fibers as fillers to a polymer matrix. This study used mahogany and mango wood sawdust as reinforcement materials, while high-density polyethylene (HDPE) and polyvinyl chloride (PVC) were used as matrices. The investigated data in this study comprises four different (10, 20, 30, and 40) weight percentages (wt%) of mahogany and mango sawdust paired with corresponding wt% (90, 80, 70, and60) of HDPE and PVC matrices. The extrusion method produced composites with different amounts of sawdust and polymer matrices. Wood polymer composites were characterized by examining their mechanical properties, and scanning electron microscopy (SEM) was employed to analyze their morphology. The results showed that the maximum tensile strength was obtained from the 20% for both sawdust composites. The ultimate tensile strength was recorded at 15.28 MPa for Mahogany sawdust-HDPE (Mh-HDPE) composite, whereas the Mahogany sawdust-PVC (Mh-PVC) exhibited the lowest tensile strength at 2.38 MPa. In addition, HDPE-based composite shows higher tensile strength (11.56 MPa) with Mango sawdust than PVC-based composites (2.28 MPa). Tensile strength, and impact strength of the fabricated composites were also assessed by ASTM standards. The maximum impact strength was obtained at 10wt% of sawdust for all four composites investigated in this study. It was also observed that impact strength significantly decreased with the increase of fiber percentage in the composite. These results demonstrated the highest mechanical properties of the Mh-HDPE than the other composites, which SEM further investigated. The morphological analyses confirmed uniform mixing of sawdust and polymer matrices, evident by the absence of no pores, cavities, or voids in the prepared composites. [ABSTRACT FROM AUTHOR]

This study was based on the experimental performance evaluation of a wood polymer composite (WPC) that was synthesized by incorporating untreated and treated rice husk (RH) fibers into a polypropylene random copolymer matrix. The submicron-scale RH fibers were alkali-treated to modify the surface and introduce new functional groups in the WPC. A compatibilizer (maleic anhydride) and a thermos-mechanical properties modifier (polypropylene grafted with 30 % glass fiber) were used in the WPC. The effects of untreated and treated RH on the WPC panels were studied using FESEM, FTIR, and microscope images. A pin-on-disk setup was used to investigate the bulk tribological properties of PPRC and WPC. The complex relationship between the friction coefficient of different loading of RH fibers in the WPC, as a function of sliding distance, was analyzed along with the temperature and morphology of the surface. It was observed that untreated RH acted as a friction modifier, while treated RH acted as a solid lubricant. Microhardness was calculated using the QCSM module on nanoindentation. It was found that untreated RH led to an increase in microhardness, while treated RH caused a decrease in hardness compared to PPRC.

Wood veneer based composites have a great demand in present market as the material can utilize small diameter plantation timbers grown at short rotation cycle. This paper presents preparation and characterization of hybrid composites made of wood veneer and wood polymer composite. The study explored utilization of wood polymer composite as an adhesive for bonding veneers replacing formaldehyde-based adhesives. Wood polymer composite containing 40 % bamboo particles embedded in the matrix of polypropylene was used in sheet form to bind the veneers of Melia dubia wood. The composites were prepared in both laminated veneer lumber and plywood configurations. The assessment of physical and mechanical properties indicated that the properties of wood polymer composite contribute significantly to the properties of the hybrid composites. The density of the resultant composites was significantly higher (0,69 g/cm3 – 0,75 g/cm3) than conventional plywood or laminated veneer lumber. Among mechanical properties, there was no statistical difference in tensile and flexural strength of plywood and laminated veneer lumber configuration. Modulus of elasticity and compressive strength of laminated veneer lumber configuration were significantly higher than plywood. Glue shear strength and internal bond strength of the composites indicated acceptable bonding properties of wood polymer composite which suggests the potential application of these composites as a binding agent for wood veneers. These composites could be a special class of laminated composites with no formaldehyde emission hazards.

Issues of environmental sustainability attract more and more attention to polymeric systems that can be considered environmentally friendly. A class of materials that meets the demand for a lower environmental impact are Wood Polymer Composites, or WPCs. These are thermoplastic polymers compounded with wood fibers or flour, usually coming from industrial or agricultural waste. With these materials, the greatest benefit is obtained by increasing the wood content, thus reducing the percentage of polymeric matrix. On the other hand, two of the main drawbacks coming from an increase in the wood content are brittleness and a significant reduction in processability. In this work, concentration will be on reducing brittleness by adding different amounts of a toughening agent (i.e., a thermoplastic elastomer) and on finding the optimal combination between processing conditions and elastomer content. This target will be obtained by comparing the tensile properties of all composites that are produced with different extrusion conditions with their apparent density. [ABSTRACT FROM AUTHOR]

From a fiber composite point of view, an elongated softwood particle is a composite consisting of several thousand tracheids, which can be described as fiber wound hollow profiles. By knowing their deformation behavior, the deformation behavior of the wood particle can be described. Therefore, a numerical approach for RVE- and FEM-based modelling of the radial and tangential compression behavior of pine wood tracheids under room climate environment is presented and validated with optical and laser-optical image analysis as well as tensile and compression tests on pine sapwood veneer strips. According to the findings, at 23 °C and 12% moisture content, at least 10 MPa must be applied for maximum compaction of the earlywood tracheids. The latewood tracheids can withstand at least 100 MPa compression pressure and would deform elastically at this load by about 20%. The developed model can be adapted for other wood species and climatic conditions by adjusting the mechanical properties of the base materials of the cell wall single layers (cellulose, hemicellulose, lignin), the dimensions and the structure of the vessel elements, respectively. [ABSTRACT FROM AUTHOR]

Wood fiber filled high density polyethylene composites (WPCs) were prepared using twin screw extruder and maleated polyethylene as a coupling agent. Bamboo fibers were initially treated with alkali (NaOH), boric acid - borax (Ba-Bx) and borax (Bx). The treated and untreated fibers were used in combination with ammonium polyphosphate (APP) to investigate their synergistic effects on thermal stability, flame retardancy and mechanical properties. Alkali pretreatment (5 % NaOH) of fibers showed significant improvement in performance of APP by increasing thermal stability in WPCs. The derivative thermogravimetric (DTG) results indicate significance of Ba-Bx in promoting char induction at lower temperatures (340 ºC) and thereby, improved the thermal stability in WPCs. Flammability decreased with addition of flame retardant additives. As compared to pure WPCs, composites containing APP 10 % / Ba-Bx 5 % exhibited maximum reduction in average heat release rate (HRR) by 69 %, peak heat release rate (PHRR) by 59 %, total heat released rate (THR) by 48 % and also increased time to ignition (TTI) by 62 %. However, no significant difference was found among the combinations i.e., APP with or without compounds towards reducing the flammability of WPCs. The strength properties also reduced significantly when boron compounds were added along with APP. In general, APP alone (15 %) is enough for imparting thermal stability and flame retardancy in WPCs.

Polymer composite materials based on natural fiber such as wood had been widely used for research purposes and engineering interests. The interest in wood reinforced polymer composites had grown quickly due to their better performance in aspects of mechanical properties compared to pure wood. In this study, wood sawdust of diospyros (kayu malam) and dialium (keranji) were chosen to be incorporated into an epoxy‐based polymer composite. The wood is made into sawdust, which was treated with boric acid and hydrogen peroxide. Surface treatment with these reagents was used to improve the mechanical properties of the polymer composite compared to untreated wood polymer composite. Sawdust reinforced epoxy composite that was fabricated are with different weight percentages from 0 % (no wood), 5 %, 10 %, 15 % to 20 % wt % for comparison on their tensile, flexural, and impact strength properties. Tensile, flexural, and impact tests were performed to determine the changes in mechanical properties where it was found that tensile strength had increased by 34 percent with an optimum keranji and kayu malam fiber weight of 15 wt % for both boric acid and hydrogen peroxide treatments. For flexural strength, in both wood fibers, the optimum fiber weight was found to 15 wt %, and the addition of wood had increased the strength by 57 percent. As for impact strength, it decreased as the weight of fiber increased, where it was assumed that the addition of wood might have increased the crack initiation. Adhesive bonding between hydrophilic wood sawdust and the hydrophobic epoxy polymer was the phenomenon that was focused on this research. The range of optimum weight percentage of sawdust would be determined from the experiment result. [ABSTRACT FROM AUTHOR]

From a fiber composite point of view, an elongated softwood particle is a composite consisting of several thousand tracheids, which can be described as fiber wound hollow profiles. By knowing their deformation behavior, the deformation behavior of the wood particle can be described. Therefore, a numerical approach for RVE- and FEM-based modelling of the radial and tangential compression behavior of pine wood tracheids under room climate environment is presented and validated with optical and laser-optical image analysis as well as tensile and compression tests on pine sapwood veneer strips. According to the findings, at 23 °C and 12% moisture content, at least 10 MPa must be applied for maximum compaction of the earlywood tracheids. The latewood tracheids can withstand at least 100 MPa compression pressure and would deform elastically at this load by about 20%. The developed model can be adapted for other wood species and climatic conditions by adjusting the mechanical properties of the base materials of the cell wall single layers (cellulose, hemicellulose, lignin), the dimensions and the structure of the vessel elements, respectively.

For investigation on the effect of silane compound on practical properties of poplar wood polymer composite, samples were impregnated using vacuum/pressure method with 3-trimethoxysilyl propyl methacrylate, and subsequently with styrene, methyl methacrylate, and mixtures of styrene/methyl methacrylate. Field emission scanning electron microscopy observations and Fourier transform infrared analysis indicated that styrene/methyl methacrylate copolymerized with 3-trimethoxysilyl propyl methacrylate and the resultant polymer tightly contacted to the wood cell walls without noticeable gaps. Impregnation with styrene resulted in a higher density of wood polymer composite compared to methyl methacrylate, which was more obvious in the presence of 3-trimethoxysilyl propyl methacrylate. Mechanical strength of the wood polymer composites improved and the highest strength was obtained for the 3-trimethoxysilyl propyl methacrylate/styrene/methyl methacrylate-modified samples. Maximum hardness was found in 3-trimethoxysilyl propyl methacrylate/styrene/methyl methacrylate-modified samples due to the cross-link formation between modified cell wall and polymer. [ABSTRACT FROM AUTHOR]

Wood plastic composites (WPCs) have often been used in consumer applications, automotive industry and exterior construction. WPCs consist mostly of wood and thermoplastic polymer. WPCs can have superior outdoor durability and much lower maintenance costs than regular wood. WPCs can be used instead of wood. Styrene maleic anhydride (SMA) is used in plastic composites for the automotive industry and also in engineering applications. SMA wood composites, as one of the WPCs using wood fibers as reinforcing fillers, produces composites with mechanical properties that are stiffer and stronger than he neat polymer. This paper evaluates the feasibility of using foamed SMA copolymer composites in wood applications. Although it is currently used in the automotive industry and construction industry, this copolymer presents interesting opportunities for wood applications.

This study was based on the experimental performance evaluation of a wood polymer composite (WPC) that was synthesized by incorporating untreated and treated rice husk (RH) fibers into a polypropylene random copolymer matrix. The submicron-scale RH fibers were alkali-treated to modify the surface and introduce new functional groups in the WPC. A compatibilizer (maleic anhydride) and a thermos-mechanical properties modifier (polypropylene grafted with 30 % glass fiber) were used in the WPC. The effects of untreated and treated RH on the WPC panels were studied using FESEM, FTIR, and microscope images. A pin-on-disk setup was used to investigate the bulk tribological properties of PPRC and WPC. The complex relationship between the friction coefficient of different loading of RH fibers in the WPC, as a function of sliding distance, was analyzed along with the temperature and morphology of the surface. It was observed that untreated RH acted as a friction modifier, while treated RH acted as a solid lubricant. Microhardness was calculated using the QCSM module on nanoindentation. It was found that untreated RH led to an increase in microhardness, while treated RH caused a decrease in hardness compared to PPRC., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors. Published by Elsevier Ltd.)

The European Commission's ambitious construction and demolition waste (CDW) material recovery target has placed pressure on Finland to increase its CDW material recovery rate. It has been identified that using CDW fractions, e.g. waste wood, plastic, mineral wool and plasterboard, as raw materials for wood polymer composites (WPCs) may help in reaching the CDW material recovery target. The objectives of this study were to assess the environmental impacts of WPC production using specific CDW fractions, namely wood, plastic, plasterboard and mineral wool, as raw materials, and to compare these impacts with the baseline situation where these CDW fractions are treated with conventional waste treatment methods such as landfilling and incineration. The study focused primarily on the depletion of fossil hydrocarbons and climate change. The results indicate that, when compared to the baseline situation, the environmental impacts of CDW management can be decreased when CDW fractions are used in WPC production. By substituting WPCs for plastic or aluminium, considerable environmental benefits can be achieved in terms of the aforementioned impact categories. Due to the differences in the physical and mechanical properties of WPCs compared to plastic and aluminium, WPCs cannot necessarily substitute them in a mass-based ratio of 1:1. This was acknowledged in the study by identifying minimum substitution rates for different materials. For instance, the produced WPCs should substitute at least 6% of plastic and 8% of aluminium in order to decrease the impact on climate change compared to the advanced waste management scenario. Therefore, in applications where WPCs can be used as a substitute for these materials, WPC product design and development should be prioritised. • Environmental impacts of WPC production as a part of CDW management are assessed. • WPC production decreases the environmental impacts of CDW management. • Virgin material substitution has strong influence on the results. • The produced WPCs should primarily substitute plastic or aluminium. • Substituting wood by WPCs is not environmentally recommendable. [ABSTRACT FROM AUTHOR]

Copyright of Wood Industry / Drvna Industrija is the property of Drvna Industrija and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of wood fibers is a deeply investigated topic in current scientific research and one of their most common applications is as filler for thermoplastic polymers. The resulting material is a biocomposite, known as a Wood Polymer Composite (WPC). For increasing the sustainability and reducing the cost, it is convenient to increase the wood fiber content as much as possible, so that the polymeric fraction within the composite is thereby reduced. On the other hand, this is often thwarted by a sharp decrease in toughness and processability—a disadvantage that could be overcome by compounding the material with a toughening agent. This work deals with the mechanical properties in tension and impact of polypropylene filled with 50 wt.% wood flour, toughened with different amounts (0%, 10%, and 20%) of a polypropylene-based thermoplastic vulcanizate (TPV). Such properties are also investigated as a function of extrusion processing variables, such as the feeding mode (i.e., starve vs. flood feeding) and screw speed. It is found that the mechanical properties do depend on the processing conditions: the best properties are obtained either in starve feeding conditions, or in flood feeding conditions, but at a low screw speed. The toughening effect of TPV is significant when its content reaches 20 wt.%. For this percentage, the processing conditions are less relevant in governing the final properties of the composites in terms of the stiffness and strength.

The study investigated the possibility of using wood flour obtained from fast-growing willow chips ( Salix viminalis ) as an alternative for standard hard- and softwood flours used in the production of wood polymer composites (WPCs). The composites contained willow flour and polyethylene matrix (OPCs) were prepared, characterized and compared with other WPCs which had been filled with hard- or softwood flours. Moreover, the structural and functional properties were investigated and discussed. Greater hemicellulose contents and lower lignin contents in OPCs resulted in better impact strength values of those materials. Which is interesting, the chemical composition of OPCs was found similar to that of hardwood-filled WPCs, but at the same time no deterioration was noted in the strength properties of OPCs, which was observed and which is typical for that kind of WPCs. That can be explained by a slightly higher share of cellulose in OPCs (in comparison with hardwood-filled WPCs) and also by a greater number of hydroxyl groups which may have some positive contribution to the structural strength of the composites. The results showed that the OPCs had slightly better mechanical properties against various WPCs. Hence, the willow flour can be used in the production of WPCs as a cheaper alternative for the hardwood filling materials. [ABSTRACT FROM AUTHOR]

In most countries, fibreboards are not recovered after utilization but burned for energy production. This study aims at recovering fibres from industrial fibreboards and reusing them as reinforcement elements in wood polymer composites (WPC). Recovered fibre (RF) material was generated by the thermo-hydrolytic disintegration of medium and high density fibreboards bonded with urea-formaldehyde resin. Various formulations of RF and polypropylene were used with or without the addition of the coupling agent to manufacture WPC using a co-rotating extruder. Test specimens were produced via injection moulding whereby those containing ‘virgin’ fibres served as a reference with respect to mechanical and physical properties. WPC formulations containing RF and ‘virgin’ fibres exhibited similar results, but composites containing RF exhibited improved mechanical and water-related properties, especially without coupling agent. The study indicates that recovered fibres are suitable to produce WPC with very similar physico-mechanical properties as those from ‘virgin’ fibres. [ABSTRACT FROM AUTHOR]

Wood polymer composites were prepared by consecutive impregnation with maleic anhydride (MAN) and methyl methacrylate (MMA). Samples impregnated with MAN alone, were heated at 120°C and 150°C for 4 and 8 h. Based on the Fourier transform infrared (FT-IR) analysis and soaking-drying test results, treatment with MAN at 150°C for 4 h resulted in formation of stable crosslinks. In the second stage, MMA was used forin situpolymerization within MAN-treated wood. Field emission scanning electron microscopy observation and FT-IR analysis indicated that MMA copolymerized with MAN, and the resultant polymer filled up the lumen and is also grafted on to the cell wall. Improvement of water repellency and dimensional stability were observed in the treated samples, particularly in combined treated samples. The MAN/MMA treatment improved interaction between polymer and wood. [ABSTRACT FROM PUBLISHER]

The rheological properties of a 50 wt.% wood flour filled polypropylene have been measured at 195°C using an instrumented slit die attached to a single screw extruder. Wall slip and non-Newtonian effects have been corrected through the Mooney and Rabinowitsch procedures, thus equations for viscosity and wall slip have been obtained. Interestingly, the pressure drop profiles calculated using these equations are not perfectly consistent with the experimental pressure measurements, in that the theoretical curves overestimate the experimental data. An explanation has been sought by assuming that slip velocity increases in the last portion of the slit die, i.e. close to the exit, where pressure drops down considerably. A pressure dependent slip model has been then proposed, its specific equations numerically solved and the results fitted to the experimental pressure data. The fitting is better than the one coming from the model that comprises slip depending on shear stress only, thus, for the fluid that has been studied, the assumption of pressure dependent slip appears to be justified. [ABSTRACT FROM AUTHOR]

The modification of pristine nanoclay and its application in wood plastic composite (WPC) have been investigated in this paper. Pristine nanoclay was modified using transition metal ion (TMI) which was copper (II) chloride to achieve good dispersion and to improve properties of WPC. The morphology, composition, structure, and thermal stability of TMI-modified nanoclay were studied by field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) analysis. The pristine (WPC/MMT) and TMI-modified (WPC/MMT Cu) nanoclay based WPC were made from polypropylene (PP), wood flour (WF), and maleic anhydride grafted polypropylene (MAPP) coupling agent. Pristine and modified nanoclay with different concentration (1 wt%, 2.5 wt%, 4 wt% and 5 wt%) were used as a reinforcing filler for WPC. Mechanical, physical, morphological, and thermal properties of the prepared composites were evaluated. Result exhibit that at 1 wt% nanoclay content, the tensile, flexural, and impact strength of WPC/MMT improved by approximately 6%, 4%, and 8%, respectively, compared to WPC without nanoclay. For the WPC/MMT Cu, the improvements in these properties were about 2.6, 2.1 and 3 times higher than the WPC/MMT. The physical and thermal properties also improved by incorporating modified nanoclay in WPC. [ABSTRACT FROM AUTHOR]

Copyright of Wood Industry / Drvna Industrija is the property of Drvna Industrija and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Environmental performance is an important promotive factor in the future use of wood polymer composites. In this study, the environmental effects of replacing virgin glass fibers with recycled mineral wool fibers, as well as replacing virgin polypropylene with recycled polypropylene are investigated. Furthermore, the environmental performance of two different end-of-life options for composite waste, incineration for energy use and landfill deposition is evaluated. The recycled mineral wool was found to have better environmental performance compared to glass fiber in every impact category assessed. The utilization of recycled polypropylene proved to be advantageous in global warming potential and abiotic depletion categories. It was found that the end-of-life management of composite waste has an important role in the environmental performance of composites. Incineration of composite waste for energy use had better performance compared to landfill deposition in all the categories assessed, except for global warming potential. It is concluded that while the environmentally optimal recycling method for polypropylene waste must be evaluated case by case, recycled mineral wool seems to provide an environmentally superior option to glass fiber in wood polymer composite applications where properties obtainable by the use of a mineral filler are required. [ABSTRACT FROM AUTHOR]

Wood polymer composites were manufactured from several types of tropical wood species by impregnating the woods with acrylonitrile monomer solution. The physical and mechanical properties of wood polymer composites were then investigated in this study. The vacuum-pressure method was employed to impregnate wood samples with monomer and in situ polymerization. Acrylonitrile reacted and incorporated with wood, which was confirmed through Fourier transform infrared spectroscopy and scanning electron microscopy test analysis. The mechanical properties of wood samples in terms of modulus of elasticity and compressive modulus were found to be improved on acrylonitrile treatment. Besides, the fabricated wood polymer composite samples had lower water absorption and higher surface hardness (Shore D) value as compared to their corresponding raw one. For wood polymer composites, a significant improvement was found in physical and mechanical properties compared to the raw woods. [ABSTRACT FROM PUBLISHER]

This investigation concerns about the thermal and decay resistance properties of tropical wood polymer composites. Wood polymer composites were prepared from several types of tropical wood species by impregnating the woods with ethyl methacrylate that was combined with a cross-linker, hexamethylene diisocyanate. Thermal properties of wood polymer composites in terms of thermogravimetric analysis and differential scanning calorimetry were evaluated, and an improvement in thermal stability was found on ethyl methacrylate and ethyl methacrylate–hexamethylene diisocyanate treatment. A significant improvement in decay resistance was also identified in wood polymer composites that were treated with ethyl methacrylate, and also, with ethyl methacrylate–hexamethylene diisocyanate. The improvement in properties was observed as more potential with ethyl methacrylate–hexamethylene diisocyanate combination rather than ethyl methacrylate. [ABSTRACT FROM AUTHOR]

Abstract: Wood polymer composite (WPC) was obtained by vinyl monomers such as styrene (ST), methylmethacrylate (MMA), and their mixture (50:50; volume:volume) of treated sapwood of Scots pine (Pinus sylvestris L.). Boric acid (BA) and borax (BX) mixture was impregnated into wood at 1% concentration prior to monomer treatment. Wood polymer composite with and without BA and BX mixture pretreatment was evaluated in terms of some physical, biological, mechanical, and fire properties. Vinyl monomers considerably improved physical properties of wood such as increased antiswelling efficiency (ASE), specific gravity (SG), and reduced water absorption (WA) levels of wood. Modulus of elasticity (MOE) and modulus of rupture (MOR) were also higher than that of untreated control specimens. The treated wood proved to be resistant against decay fungi, Tyromycetes palustris and Coriolus versicolor. Boric acid and borax mixture pretreatment imparted WPC total resistance against both decay fungi. Although, ASE, MOE, and MOR levels of WPC pretreated with BA and BX mixture were reduced in some extent, it improved fire resistance of wood. [Copyright &y& Elsevier]

Abstract: The recycling of internal waste of poly(vinyl chloride) (PVC) and wood fibre-reinforced PVC composite was investigated and compared. Twenty extrusion-milling cycles were performed and the mechanical and thermal properties evaluated. This comparison provided evidence of the influence of the vegetable fibres on the thermo-mechanical degradation of the composite material. Up to five cycles, the composite properties remained stable. But after 10 cycles and especially at 20 cycles, the flexural strength increased, whereas the other mechanical properties remained almost constant. At the same time, a decrease of the degradation temperature revealed a deterioration of the molecular structure. The PVC properties remained constant, whereas a great increase in the impact strength was observed after 20 cycles without deterioration of the molecular structure. The different behaviours between the composite and the PVC were explained by the influence of the fibres, which accelerated the PVC degradation, characterized by dehydrochlorination followed by crosslinking reactions. [Copyright &y& Elsevier]

The composites of banana, hemp, and agave with HDPE resin were separately prepared in different ratios, 60:40, 55:45, 50:50, and 45:55 (wt/wt). These fibers were also treated with maleic anhydride and the effect of maleic anhydride was studied on surface resistivity and volume resistivity of wood polymer composites. The surface resistivity decreases with an increase in fiber content in the composites, while volume resistivity increases. The maximum surface and volume resistivities were observed in untreated banana fiber composite, while minimum surface resistivity and volume resistivity were found in maleic anhydride-treated agave fiber composite. The decrement in volume resistivity and surface resistivity is due to the increment in cross-linking between polymer and fiber by treatment with maleic anhydride. [ABSTRACT FROM AUTHOR]

In the present work, wood polymer composites from agro-waste (banana, hemp, and agave fibers) and novolac resin were prepared. Banana, hemp, and agave fibers were treated with novolac resin for the formation of their composites in the different ratios of 60:40, 55:45, 50:50, 45:55, and 40:60 (wt/wt). These fibers were also treated with maleic anhydride and the effect of maleic anhydride was studied on surface resistivity and volume resistivity of wood polymer composites. The maximum surface and volume resistivity is found in maleic anhydride treated and untreated banana fiber composite, respectively. The treatment of maleic anhydride improves the surface resistivity of respective fiber composites. Maleic anhydride treated banana fiber composite shows maximum surface resistivity while untreated agave fiber composite shows minimum surface resistivity. [ABSTRACT FROM AUTHOR]

Poplar wood flour and linear low density polyethylene (LLDPE) composites were prepared by varying percentage of wood flour in LLDPE. The composites were synthesized via single screw extruder and then injection moulded to tensile test specimens. Maleic anhydride grafted LLDPE was used as a compatibilizer. The tensile and thermal properties of wood polymer composites were investigated to optimize the wood flour content into the polymer matrix.. The composite having 30% of wood flour in LLDPE (LPW3) was found to have the maximum tensile strength, almost double than for LLDPE. Its tensile modulus was also recorded as three times than that of LLDPE. The optimized composite (LPW3) was then subjected to gamma radiation of variable dose, ranging from 25 to 150 kGy. The tensile strength was found to be the maximum at 100 kGy with comparatively better tensile modulus. The onset degradation temperature of LLDPE is evaluated to be 442 °C and that of LPW3 before and after irradiation ranges from 421 to 433 °C. The activation energies of degradation, calculated by multiple heating rate kinetic methods of both non-radiated and radiated optimized composite were found to be relatively higher than that of LLDPE. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques were also used in the present study. • LLDPE/poplar wood flour composites were synthesized by the method of extrusion and casted into shape by injection moulding. • The effect of gamma radiation of various doses is characterized in terms of thermal and tensile properties. • Kinetic parameters were evaluated by multiple heating rate methods viz. Coats-Redfern (modified) and O–F–W. [ABSTRACT FROM AUTHOR]