Influence of nanoclay on properties of HDPE/wood composites (original) (raw)
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Physical properties of polyethylene-wood fiber-clay nanocomposites
Journal of Applied Polymer Science, 2010
In this study, nanocomposites based on polyethylene (PE), maleic anhydride grafted polyethylene (MAPE), recycled newsprint fibers, and organically modified montmorillonite (nanoclay) were made by injection molding. The effects of two variable factors, namely, the nanoclay and MAPE contents, on the composite physical properties were examined. All blends were made with a fiber-to-PE weight ratio of 30 : 70. The results show that the addition of MAPE and nanoclay in the nanocomposite formulation significantly improved both the stability and water absorption properties. The improving effect of MAPE could be explained by the improvement in the quality of adhesion between the polymer and fibers. Nanocomposites containing 5 wt % MAPE and nanoclay exhibited minimum water absorption during the whole duration of immersion. The results of this research study show that wood-plastic composites treated with a coupling agent and nanoclay will be desirable as building materials for outdoor applications.
Effect of Nanoclay on the Mechanical and Morphological Properties of Wood Polymer Nanocomposite
Journal of Reinforced Plastics and Composites, 2009
Polypropylene/wood flour composites with different nanoclay and maleic anhydride grafted polypropylene (PP-g-MA) contents were fabricated by melt compounding and then by injection molding. The mechanical properties, such as flexural modulus, tensile modulus, elongation at break, and impact strength, were evaluated. Results indicated that the flexural modulus, tensile modulus, and elongation at break increases with increase of nanoclay up to 3 phc at the same concentration of PP-g-MA, and then decreases. However, the impact strength of the composites decreases with increased nanoclay loading. Also, the effect of compatibilzer was positive in terms of enhancing the mechanical properties of the composites. The morphology of the nanocomposites has been examined by using X-ray diffraction and transmission electron microscopy. Morphological findings revealed that intercalation form, the sample with 3 phc concentration of clay, which implies the formation of the intercalation morphology an...
Effect of bark flour on the mechanical properties of HDPE composites
Usak University Journal of Material Sciences, 2014
The objective of this study was to evaluate the replacement of wood flour by Turkish pine bark residues for production of wood plastic composites. High density polyethylene was chosen as matrix and seven different compositions were used for production of composites. In order to compare the effect of bark residues flour as a filler, bark residues-HDPE composites were produced with various wt% bark residues loading (10, 20, 30 and 40 wt%). Bark residues filled HDPE pellets were produced by using a twin-screw extruder, then 25 cm (l) x 25 cm (w) and 2 mm (t) composites were produced with compression molding technique according to ASTM D4703-10. For each composition, three composites were produced. Tensile and flexural tests were performed with a Universal Testing machine. Impact strength was measured with a Zwick HIT5.5P Impact Testing machine. Tensile and impact strength of the composites decreased with increasing bark flour loading whereas bending strength and modulus of eleasticity values were improved with addition of the bark flour. All produced bark flour filled composites showed better modulus of elasticity and bending strength properties than ASTM D6662-13 standard requirements for polyolefinbased plastic lumber. Morphological properties of bark residues-HDPE composites were characterized by scanning electron microscopy (SEM) technique.
Study on properties of nanocomposites based on HDPE LDPE PP PVC wood and clay
Wood polymer nanocomposite (WPC) was prepared by solution blending of high density polyethylene, low density polyethylene, polypropylene and polyvinyl chloride (1:1:1:0.5) with wood flour and nanoclay. Xylene and tetrahydrofuran were used as solvent and the ratio was optimized at 70:30. TEM study revealed better dispersion of silicate layers in WPC loaded with 3 wt% of clay. WPC loaded with 3 wt% nanoclay exhibited higher thermal stability compared to WPC loaded with 1 and 5 wt% clay. The storage and loss modulus were found to enhance on incorporation of clay to WPC. The damping peak was found to be lowered by the addition of clay to WPC. Limiting oxygen index value increased due to incorporation of nanoclay. WPCs were subjected to exposure to cellulase producing Bacillus sp. and it showed the growth of bacteria as revealed by SEM study. Mechanical properties of WPC decreased due to degradation by bacteria. Water vapour uptake of WPC decreased due to addition of nanoclay.
Bamboo–Fiber Filled High Density Polyethylene Composites: Effect of Coupling Treatment and Nanoclay
Journal of Polymers and the Environment, 2008
High density polyethylene (HDPE)/bamboo composites with different nanoclay and maleated polyethylene (MAPE) contents were fabricated by melt compounding. The compounding characteristics, clay dispersion, HDPE crystallization, and mechanical properties of the composites were studied. The equilibrium torque during compounding decreased with use of clay masterbatch and increased with the addition of MAPE. The X-ray diffraction (XRD) data showed that the clay was exfoliated only when 1% clay was added to pure HDPE without MAPE. For HDPE/bamboo systems, MAPE was necessary to achieve clay exfoliation. For pure HDPE system, both dynamic and static bending moduli increased, while impact strength decreased with increased clay loading. For the HDPE/bamboo fiber composites, tensile strength, bending modulus and strength were improved with the use of MAPE. The use of the clay in the system led to reduced mechanical properties. Techniques such as pre-coating fibers with clay-MAPE mixture are needed to enhance the synergetic effect of the clay and bamboo fiber on the composite properties in the future study.
Polymers
The use of wood plastic composites (WPC) is growing very rapidly in recent years, in addition, the use of plastics of renewable origin is increasingly implemented because it allows to reduce the carbon footprint. In this context, this work reports on the development of composites of bio-based high density polyethylene (BioHDPE) with different contents of pinecone (5, 10, and 30 wt.%). The blends were produced by extrusion and injection-molded processes. With the objective of improving the properties of the materials, a compatibilizer has been used, namely polyethylene grafted with maleic anhydride (PE-g-MA 2 phr). The effect of the compatibilizer in the blend with 5 wt.% has been compared with the same blend without compatibilization. Mechanical, thermal, morphological, colorimetric, and wettability properties have been analyzed for each blend. The results showed that the compatibilizer improved the filler–matrix interaction, increasing the ductile mechanical properties in terms of ...
Journal of Applied Polymer Science, 2009
The thermal sensitivity, nucleating ability, and nonisothermal crystallization of high-density polyethylene (HDPE) with different wood fillers during wood/HDPE melt processing were investigated with thermogravimetric analysis and differential scanning calorimetry. The results showed that the wood degraded at a lower temperature than HDPE. The thermal decomposition behavior was similar across wood species. The most remarkable dissimilarities were observed between wood and bark in the decomposition rate around a processing temperature of 300°C and in the peak temperature location for cellulose degradation. The higher degradation rate for bark was explained by the devolatilization of extractives and the degradation of lignin, which were present in higher amounts in pine bark. The nucleating ability for various wood fillers was evaluated with the crystalline weight fraction, crystal conversion, crystallization half-time, and crystallization temperature of the HDPE matrix. The nucleation activity improved with the addition of wood particles to the HDPE matrix. However, no effect of wood species on the crystal conversion was found. For composites based on semicrystalline matrix polymers, the crystal conversion may be an important factor in determining the stiffness and fracture behavior. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Weak flexural properties of wood plastic composites (WPCs) limit their structural application. Recently investigation of nano particles looks promising to enhance bending properties of WPCs. In this study, the authors have investigated the effect of different concentrations of nanoclay (modified montmorillonite) and coupling agent on the mechanical and micro-structural properties of polypropylene/ wood-fiber composites. We Bath internal mixer in certain processing conditions used for making the samples and then all samples molded using injection molding for making samples for performing mechanical measurements. Samples prepared in four different concentration of nanoclay 0, 1, 3 and 5 wt% (total weight) and two different concentrations of maleic anhydride grafting (MAPP) 5 and 10 wt%. Mechanical results indicate that both flexural and impact strength of the composites increasing in sample containing 3% nano clay. In other trend, Scanning Electron Microscope (SEM) images show better ...
In this study, the effects of oxidized polypropylene, as a compatibilizer, and Nano-clay particles in improving the thermal properties of wood plastic composites are investigated. For this purpose, polypropylene polymer was oxidized in the vicinity of the air oxygen for 2 hours. Then, in order to produce the samples, Nano-clay particles at three levels (0%, 2% and 4%) were mixed with wood fibers, polypropylene polymer and the compatibilizer. Finally, the samples with thickness of 2mm and dimensions of 15×15cm were made by using hot press. For more precise investigation, the morphology of wood plastic composites was studied by using X-rays diffraction and electronic microscope images. Thermal properties of the composites were evaluated through thermal and differential analyses. The results of the thermal tests demonstrated that the addition of oxidized polypropylene and Nano-clay particles significantly improve the thermal properties of wood plastic composites. Furthermore, increment of Nano-clay particles content additionally improves thermal stability of the composites and also reduces the released heat amount during the thermal degradation. In addition, TEM images showed that the dispersion of Nano-clay particles in the composite has an intercalation structure. This subject also verified by the X-rays diffraction and it is an evidence of better thermal stability of the achieved wood plastic composites.
Polymer Engineering & …, 2007
Despite many advantages of wood-polyethylene composites, the shortcomings of this kind of composite include relatively low modulus, low notched impact resistance, relatively large thermal expansion, as well as substantial creep. In this article, in addition to using maleic anhydride grafted polyethylene as compatibilizer, organoclay was introduced into the polyethylene matrix so as to further enhance the thermal and mechanical performance. First, the influence of maleic anhydride grafted polyethylene type and loading on the morphology and properties of wood/HDPE composites was studied. Then, the effects of organoclay loading and of the compounding procedure on the wood/HDPE composites were investigated. The compatibilization was found to result in better polymer impregnation on the wood, reduced linear thermal expansion coefficients, and significantly improved mechanical properties. Incorporation of organoclay further reduced the thermal expansion and elevated the heat deflection temperature. More compatibilizer is needed to maintain the mechanical properties with the presence of clay. POLYM. ENG.