Properties Of Wood Plastic Composites Research Articles

Corncob residual reinforced polyethylene composites considering the biorefinery process and the enhancement of performance

Abstract Aiming to improve the economic feasibility of the corncob biorefinery process, fibers, including the corncob bagasse, xylose-extracted corncob residue and the ethanol-processing residue, were used as the reinforcing phase for the preparation of wood plastic composites (WPCs). The mechanical properties and the weathering performance of the composites were compared. The results indicated that the WPCs reinforced by the ethanol-processing residue showed balanced advantages in mechanical properties and weathering performance. The effects of the compatibilizer and the cellulose/lignin mixture on the WPC properties were further evaluated, indicating that use of 4 wt % of Polyethylene-graft-maleic anhydride (PE-g-MA) as the compatibilizer and a mixture of the EPR with lignin at a ratio of (9:1) were the optimized conditions for WPCs. The current work showed potential in making full use of the solid residue of biorefinery processes and making the waste profitable.

Heat transfer and mechanical properties of wood-plastic composites filled with flake graphite

Wood plastic composites (WPCs) are a new generation of green composites which can come mostly from recycled materials. The addition of the flake graphite (FG) fillers has a significant influence on the properties of WPCs and this study focuses on the heat transfer and mechanical properties of WPCs. The thermal conductivity increases with the increase of addition amount of FG and decreases with the increase of temperature. By comparing the temperature changes of specimens during heating and cooling process, WPCs with higher FG contents presents higher average equilibrium temperature. The WPCs adding FG fillers obtain a greater flexural modulus but a lower flexural strength due to the heterogeneous distribution of the stress. In general, the mechanical properties of WPCs decrease slightly with increasing content of the FG.

Wood particle size influence on water resistance and mechanical properties of thermally modified wood-polypropylene composites

ABSTRACTThe processing of wood produces large amounts and different types of wood residues. Currently, a part of these residues is used in the production of wood plastic composites (WPC). It is known that wood particle characteristics (size, length/diameter ratio, shape, etc.) significantly influence properties of WPC; however, for thermally modified wood, the information about these effects is limited. Therefore, the main objective of this research was to investigate how different size fractions of thermally modified wood particles influence mechanical and water resistance properties of WPC. The results showed that the particle size had a significantly smaller influence on the mechanical properties for WPC with thermally modified wood particles compared to WPC with unmodified wood particles. Additionally, the wood particle size had no effect on water absorption dynamics and ultimate water uptake in case of thermally modified wood particles. Finally, wood particle size did not affect changes in mechanical properties for re-dried WPC after 200 days of immersion in water.

The Effects of Different Types of Maleic Anhydride-Modified Polypropylene on the Physical and Mechanical Properties of Polypropylene-based Wood/Plastic Composites

Maleic anhydride-modified polypropylene (MAPP) is a compatibilizer used to improve the physical and mechanical properties of many wood/plastic composites (WPCs). The properties of WPCs containing MAPP differ according to the characteristics of the specific MAPP that it is used. In this study, the physical and mechanical properties, including shear viscosity, of polypropylene-based WPCs containing different types of MAPP were investigated before and after water absorption. The shear viscosity of MAPP increased with increasing molecular weight, but remained nearly constant for WPCs containing different types of MAPP. In dry conditions, the strongest WPC contained the MAPP with the highest acid value. The highest flexural modulus was observed with the WPC containing the MAPP with the highest molecular weight. In wet conditions, the WPC exhibiting the best mechanical properties contained a MAPP with a molecular weight of 58,000.

A comparison on untreated and alkaline treated rubberwood flour on physical and mechanical properties of wood plastic composites

The effect of the untreated and alkaline treated rubberwood flour (RWF) on water absorption, tensile and flexural properties of the wood plastic composites (WPCs) was investigated. The surface of RWF was treated by an alkaline treatment with NaOH solution of 2% w/v concentration for 24 h. The results showed that the RWF treated with alkaline could enhance the interfacial adhesion with rPP and also improve the water absorption and tensile and flexural properties of WPCs. In addition, the alkaline treatment and RWF content significantly affected the tensile and flexural strength. The alkaline treatment also increased water resistance of WPCs, which at 20% RWF content showed the lower water absorption (2.04%). The highest tensile strength (17.75 MPa) and flexural strength (35.73 MPa) of WPCs were achieved with an alkaline treatment at 30 wt% RWF. Moreover, the tensile and flexural modulus of WPCs increased with increasing RWF content (20% to 50%).

A comparison on untreated and alkaline treated rubberwood flour on physical and mechanical properties of wood plastic composites

The effect of the untreated and alkaline treated rubberwood flour (RWF) on water absorption, tensile and flexural properties of the wood plastic composites (WPCs) was investigated. The surface of RWF was treated by an alkaline treatment with NaOH solution of 2% w/v concentration for 24 h. The results showed that the RWF treated with alkaline could enhance the interfacial adhesion with rPP and also improve the water absorption and tensile and flexural properties of WPCs. In addition, the alkaline treatment and RWF content significantly affected the tensile and flexural strength. The alkaline treatment also increased water resistance of WPCs, which at 20% RWF content showed the lower water absorption (2.04%). The highest tensile strength (17.75 MPa) and flexural strength (35.73 MPa) of WPCs were achieved with an alkaline treatment at 30 wt% RWF. Moreover, the tensile and flexural modulus of WPCs increased with increasing RWF content (20% to 50%).

Some exploitation properties of wood plastic composites based on polypropylene and birch plywood sanding dust

Some exploitation properties of wood plastic composites based on polypropylene and birch plywood sanding dust

Mechanical and Physical Properties of Wood–Plastic Composites Containing Cellulose Nanofibers Added to Wood Flour

Abstract Recently, the usage of wood–plastic composite (WPC) products has increased, mainly for exterior decking. The shape of fillers is one of the important factors deciding the mechanical and physical properties of WPCs. Surface-fibrillated wood flour (WF) improves the mechanical properties of WPCs, although it requires a lot of energy and time to produce the fibrous structure during the pulverization process. Therefore, the adsorptive interaction between cellulose nanofiber (CNF) and WF by hydrogen bonding was investigated. We considered that CNF could form the fibrous structures on the WF surface by mixing CNF and WF. Also, it is thought that the addition of CNF could increase mechanical and physical properties of WPC because CNF has better physical and mechanical properties than most other fibers. The objective of this study was to produce WF-CNF fillers and to evaluate the mechanical and physical properties of WPCs containing WF-CNF fillers. WF-CNF fillers could be produced by freeze-drying after mixing WF, CNF, and water. The fibrous structures on the WF surface were observed through scanning electron microscope images of WF-CNF filler containing 3 weight percent CNF. A WPC with WF-CNF filler containing 22 percent (by weight) WF and 3 percent (by weight) CNF showed improved mechanical properties compared with WPCs without CNF. The water absorption of WPCs containing CNF was found to decrease with increasing CNF content.

The Effect of MBS Toughening for Mechanical Properties of Wood-Plastic Composites under Environmental Ageing

Wood–plastic composites (WPCs) are a promising environmentally friendly material refers to composite that contain plant powders or fibers as reinforcement and plastic matrix. In this study, an epoxy resin and Methyl metharylate-Butadiene-Styrene Copolymer (MBS) were used as a compatibilizer and toughener and were filled into recycled polyethylene terephthalate (PET) and recycled polyamide 6 (PA6) blends (PET/PA6) and filled with wood flour to prepare the WPCs. The mechanical properties of the WPCs, including the tensile, flexural, and impact properties, with different mixing ratio polymer blends of PET to PA6 (E60/A40, E50/A50, and E40/A60) were investigated under different environmental aging conditions. The experimental results showed that different environmental conditions, such as temperature and humidity, markedly changed the mechanical properties of the WPCs with different mixing ratio polymer blends. In addition, the mechanisms responsible for the interface of the WPCs were identified by studying the fracture surfaces with field emission scanning electron microscopy.

Potential use of different kinds of carbon in production of decayed wood plastic composite

This study investigated the mechanical, chemical structure and thermal properties of hot press molded wood plastic composite (WPC) panels produced from different amounts (30, 40, or 50% weight) of decayed Pinus massoniana Lamb. and polypropylene with chitosan (3 wt%) and different kind of carbon (2 wt%). The results were compared with the properties of WPC produced without carbon. The mechanical, chemical structure and thermal data showed that WPC with carbon was better than WPC without carbon, and the best condition to produce decayed wood plastic composite was hot pressing temperature at 170 °C for12 min, Carbon Nanotubes (CNT) and chitosan (CS) accounting for 2% and 3% of total mass, and the proportion of decayed wood and PVC is 40% and 60%.

The Effect of Carbon Nanotubes on the Mechanical Properties of Wood Plastic Composites by Selective Laser Sintering.

Wood-plastic composites (WPCs) made by selective laser sintering (SLS) approach of 3D printing offer many advantages over single polymer materials, such as low cost, sustainability, and better sintering accuracy. However, WPCs made via SLS are too weak to have widespread applications. In order to increase the mechanical properties of WPCs, a novel type of WPCs containing 0, 0.05, 0.1 and 0.15 wt % carbon nanotubes (CNT), 14 wt % wood fibers, 86 wt % polyether sulfone (PES) was manufactured via SLS. The experimental results showed that the addition of small amount of CNTs can significantly increase the mechanical properties of the wood/PES composite material. The tensile strength, bending strength, and elasticity modulus were 76.3%, 227.9%, and 128.7% higher with 0.1 wt % CNTs than those without CNTs. The mechanical properties of specimens first increased and then decreased with the addition of CNTs. The SEM results of the specimens’ fracture morphology indicate that the preferable bonding interfaces between wood flour grains and PES grains were achieved by adding CNTs to the composites. There are two reasons why the composites possessed superior mechanical properties: CNTs facilitate the laser sintering process of WPCs due to their thermal conductivities, and CNTs directly reinforce WPCs.

Investigation of the effect of high-fibrous filling material on the mechanical properties of wood plastic composites

In this study, wood plastic composite (WPC) materials were produced using high density polyethylene (HDPE) and wood fiber at various ratios ranging from 40% to 70%. The effects of fiber content on mechanical properties such as tensile strength, bending strength, elasticity modulus and shock resistance of these materials were investigated. In addition, maleic anhydride grafted polyethylene (MAPE) was also added to the materials, which had lowest and highest wood fiber additive, to investigate the effect of the binding agent effect. Composite samples were produced via a laboratory type twin screw extruder and test panels were prepared using hot press molding method. According to the results, the bending, tensile and shock resistances generally decreased with the increasing ratio of wood fiber in the composite material content while modulus of elasticity increased for the sample groups without coupling agent. However, the addition of the coupling agent MAPE into the material content significantly improved the mechanical properties. Especially, the addition of MAPE provided better resistance values than all sample groups without MAPE even for the samples containing 70% wood fiber. As a result, with this study, it has been shown that WPC materials with low cost, light weight, aesthetic appearance and good mechanical properties as well could be produced with high fiber ratio.

Effect of the Addition of Carbon Nanomaterials on Electrical and Mechanical Properties of Wood Plastic Composites.

Wood Plastic Composites (WPCs) are a new generation of green composites that could optimize the use of harvested trees and increase the entire value chain. In this study, the electrical and mechanical properties of WPCs containing carbon blacks (CB), flake graphite (FG) and carbon nanotubes (CNTs) have been investigated. The electrical property of WPCs is improved significantly owing to the introduction of these carbon nanomaterial fillers. The volume and surface resistivity values of the investigated composites all obviously decreased with the increase in filler content, especially CNTs, which displayed the most satisfactory results. Based on a series of laboratory experiments carried out to investigate the mechanical performance, it can be concluded that the addition of the carbon nanomaterial fillers decreases the mechanical properties of WPCs slightly with the increase in filler content because of the weak interfacial interactions between the fillers and polymer matrix.

Some Exploitation Properties of Wood Plastic Composites Based on Recycled High Density Polyethylene and Plywood Production Residues

One type of birch wood plywood by-product: plywood sanding dust (PSD) and recycled high density polyethylene (rHDPE) composites physical mechanical properties (tensile, flexural strength and modulus, impact strength and microhardness), water resistance and fluidity of the composite melts, were evaluated. These studies showed the possibility of the usage of presented by-product as an excellent reinforcement for recycled high density polyethylene matrix. It was observed that the modulus of the tensile for unmodified rHDPE+PSD composites increased up to 2.3 times, the modulus of flexural till 4 times, but the microhardness only 1.4 times. Optimal content of the PSD in recycled high density polyethylene composites could be 50 wt. %. As a coupling agent, the maleated polyethylene (MAPE) for modifying of the rHDPE+50 wt. % PSD composite was used. Due to the MAPE additives, the improvement (30-50 %) of the investigated exploitation properties was observed, but in comparison with unmodified composites the resistance of water increased up to 3.0 times. Optimal content of MAPE in rHDPE+50 wt. % PSD composition could be 3 wt.%.

Research of plastic and wood raw wastes recovery

The main aim of this paper is to present the research findings regarding the recovery possibilities of plastic and wood raw wastes. One of the recovery possibilities for mentioned raw materials is production of waste raw materials based wood-plastic composites (WPC). Lonely production process is influenced by technological and raw material parameters (type of raw material and particle size) and thus the final quality and mechanical properties of WPCs have to be determine. This paper also presents the results of realized experimental research which dealt with the determination of relationship between material parameters and mechanical properties during production of WPCs. The main goal of presented paper is to determine the mutual interaction between mechanical properties, type of the plastic matrix used in WPC, wood/plastic concentration ratio and particle size of wood sawdust used in WPC. In this paper the authors also comparing mechanical properties of WPCs based on recycled and original plastics. As a plastic matrix 100 % original HDPE and recycled HDPE originating from lids of PET bottles was used. Obtained research findings can be very helpful at WPCs production and shown the possibility of using also waste raw materials for WPC products, and thus increase the environmental responsibility with the environment protection.

Physical and Mechanical Properties of Wood Plastic Composites from Teak Wood Sawdust and High Density Polyethylene (HDPE)

Sawdust is a waste from furnitureindustry which is mostly left in the garbage or burn for landfill in hugequantities every year. Efforts to find utilization of this material haveresulted mostly in low value. However, sawdust waste can be considered as analternative to fabricate fiber reinforced polymer composites for furniturefunction. This study was undertaken to determine the physical and mechanicalproperties of wood plastic composites, which were made under laboratoryconditions by hot pressing of high-density polyethylene (HDPE) with teakwoodsawdust as filler. Seven levels of mixed flour, 10, 20, 30, 40, 50, 60 and 70%,based on the composition by weight was added to the HDPE powder with palm oilas coupling agent. A flat pressing technology, the simplest method for capableof large dimension wood plastic panel production, was used to manufacturetesting specimens in dimensions 5.8 x 7.3 cm2. Investigation of themechanical property of the composites material, according to the Americansociety for testing and materials (ASTM) method, was done by impact strengthtester. The measurement results were found that impact strength was decreased uponthe increasing of the sawdust up to 30 % mixing then gradually increased. However,by increasing mixed flour content, water resistance of the panels wasnegatively influenced. The best appearance of composites material in comparisonwith the natural woods was ~30% sawdust powder mixing. The woodplastic panels were utilized for construction of a Thai spirithouse as an outdoor decoration.

Mechanical, Flammability, and Morphological Properties of Nano-composite Plastic based on Hardwood Flour High-density Polyethylene Embedding by Nano-Zinc Oxide

The influence of the nano-zinc oxide amount was evaluated relative to the flammability behavior, as well as the morphological and mechanical properties of wood plastic composites (WPCs). The polymer amount was approximately 50 wt%, and the lignocellulose material was 50 wt%. Nano-zinc oxide was applied at six weight levels including, zero (control), 1, 2, 3, 4, and 5 phc. For all treatments, the maleic anhydride polyethylene (MAPE) amount was 2 phc. The WPCs were made using a mixture of nano zinc oxide, high-density polyethylene, and mixed hardwood flour injection molding method. The morphological and mechanical properties, such as flexural strength and modulus, were measured. Various tests were conducted with a cone calorimeter, including the amount of char residue, total smoke production, time to ignition, and heat release rate, according to ASTM E1354-92 (1992). The flexural strength and modulus of composites in samples with 5 phc nano-zinc oxide were 79.9% and 27.2% greater, respectively, than in samples without nano zinc oxide. Nano-zinc oxide enhancement to 5 phc increased the ignition time and char residue 105.1% and 121.7%, respectively, and decreased the burning rate and total amount of smoke production 20.3% and 46.0%, respectively. Scanning electron microscope results indicated the presence of nano-zinc oxide agglomerates in the sample.

The Influence of Fiber Surface Treatment and SBR as Impact Modifier on Rheological Behavior and Mechanical Properties of Wood Plastic Composite from Acrylate-Styrene-Acrylonitrile and Bagasse

Morphology, mechanical properties and rheological behavior of wood plastic composite, derived from acrylate-styrene-acrylonitrile (ASA) and bagasse which was treated with potassium permanganate (KMnO4) and using styrene butadiene rubber (SBR) as impact modifier, were reported. The effect of fiber surface treatment with KMnO4 and different amount of SBR on properties of wood plastic composite, prepared from ASA and 50 phr of bagasse, were investigated. Wood plastic composites (both treated and untreated) with varying amount of SBR, as impact modifier from 0-15 wt% of ASA, were prepared by melt-blending technique. The specimens were shaped with a compression molding machine and characterized, including morphology, impact strength, flexural properties and rheological behavior. It was demonstrated that the fiber surface treatment, using KMnO4, could effectively impove interfacial adhesion between bagasse and ASA matrix. These led to an improvement of morphology and mechanical properties such as impact strength, flexural strength and modulus. SEM micrographs revealed that the interfacial modification enhanced the interfacial adhesion between bagasse (fiber) and ASA (matrix) causing an increasing of shear stress and shear viscosity. Additionally, the effect of amount of SBR, as impact modifier, was also reported. The resulted showed that the impact strength was improved with increasing the amount of SBR (up 5 wt% of ASA) whereas, flexural strength and modulus were found to decrease with increasing SBR content.

Effects of moisture content, wood species, and form of raw materials on fiber morphology and mechanical properties of wood fiber‐HDPE composites

Use of high‐quality wood fibers as reinforcement materials in wood‐plastic composites (WPCs) significantly improves the overall performance of the resulting WPCs. This study focused on the preparation of various types of wood fibers for subsequent use in WPCs. Further, effects of moisture content, wood species, and form of raw material on the quality of prepared wood fibers and on the mechanical properties of wood fiber‐reinforced high‐density polyethylene were comprehensively investigated. The main findings indicated that the overall size of wood fibers increased significantly with the initial moisture content of raw materials; the best morphological features of fibers and the best corresponding mechanical properties of WPCs were obtained for an initial moisture content of 30 wt%. The lengths and diameters of wood fibers prepared from veneers were larger than those of fibers prepared from chips. A wood fiber diameter between 0.21 and 0.29 mm (60–80 mesh) and a length to diameter ratio between 5 and 8 yielded the best mechanical properties for the resultant products. Finally, the composites reinforced with pine fibers exhibited mechanical properties superior to those reinforced with poplar fibers. POLYM. COMPOS., 39:3236–3246, 2018. © 2017 Society of Plastics Engineers

Impulse-cyclone Drying Treatment of Poplar Wood Fibers and its Effect on Composite Material’s Properties

The fiber quality after a conventional drying treatment used for wood-plastic composites (WPCs) cannot be ascertained prior to use. Through the application of scanning electron microscopy, Fourier transform infra-red spectroscopy, and X-ray diffraction, the effect of an impulse-cyclone drying (ICD) treatment on the quality of poplar wood fiber was first investigated. Subsequently, the effect of ICD conditions, such as inlet temperature, inlet wind velocity, and feed rate on the mechanical properties of WPCs and fiber dispersibility was considered. Also, the quality of fibers and WPCs was compared to those treated via an oven-drying method. Poplar wood fibers with a moisture content of 12.4% were pre-treated at different drying conditions by ICD. The obtained fibers were compounded with high-density polypropylene. The results showed that ICD could promote the hydration of poplar wood fibers and improve the mechanical properties of WPCs. The ICD-treated wood fibers were uniformly dispersed in the plastic matrix. With the increase of inlet temperature, the number of hydroxyl and carbonyl groups of poplar fibers decreased, whereas the degree of crystallinity increased as the in-let temperature and fiber meshes was increased. This study demonstrated the feasibility for the application of an ICD treatment in the WPCs production industry.