Influence of different clays on the mechanical, thermal, and water absorption properties of recycled high-density polyethylene/wood flour hybrid composites

2017 ◽  
Vol 52 (9) ◽  
pp. 1215-1226 ◽  
Author(s):  
Ahmed Abd El-Fattah ◽  
Eman Abd ElKader

Wood plastic composites based on recycled high-density polyethylene (r-HDPE)/wood flour with the addition of organically modified clays were prepared by melt mixing and compression molding. The effect of two different types and contents of clays, bentonite and layered double hydroxide – on the mechanical, thermal, and water absorption properties of the wood plastic composites – was examined to identify the most effective clay type for wood plastic composites. It was found that incorporation of 2 wt% modified bentonite (mBNT) clay was the most effective in the composite formulation; it has significantly enhanced the properties of the wood plastic composites. The scanning electron micrographs of the fractured surfaces showed improved interfacial adhesion of the composite components. The tensile strength of wood plastic composites was increased by 9.7% when 2 wt% mBNT clay was incorporated in the composite formulation; however, the tensile strength slightly decreased as the clay content was further increased. The izod impact strength was lowered about 10.5% by 2 wt% mBNT clay. Moreover, the addition of 2 wt% mBNT clay enhanced the water resistance of the wood plastic composites by 27.5% after immersion in water for five days. On the other hand, the modified layered double hydroxide (mLDH) clay did not cause any remarkable improvement in the properties of the wood plastic composites. The tensile strength showed a decreasing trend with an increase in mLDH content. However, both clays did not improve the thermal stability of wood plastic composites. In addition, there are no noticeable changes in the values of melting temperature by increasing the content of clays. The experimental results indicated that the properties of the wood plastic composites were significantly improved when combined with the appropriate clay type and content. However, the interaction between wood flour and the intercalated clay particles as well as the processing conditions will need further study.

2010 ◽  
Vol 150-151 ◽  
pp. 379-385
Author(s):  
Qun Lü ◽  
Qing Feng Zhang ◽  
Hai Ke Feng ◽  
Guo Qiao Lai

The wood-plastic composites (WPC) were prepared via compress molding by using the blends of high density polyethylene (HDPE) and modified polyethylene (MAPE) as the matrix and wood flour (WF) as filler. The effect of MAPE content in the matrix on the mechanical properties of the matrix and WPC was investigated. It was shown that the change of MAPE content in the matrix had no influence on the tensile strength of the matrix, but markedly reduced the impact strength of the matrix. Additionally, it had significant influence on the strength of WPC. When the content of wood flour and the content of the matrix remained fixed, with increasing the content of MAPE in the matrix, the tensile strength and the flexural strength of WPC tended to increase rapidly initially and then become steady. Moreover, with the increasing of MAPE concentration, the impact strength of WPC decreased when the low content of wood flour (30%) was filled, but increased at high wood flour loading (70%).


2013 ◽  
Vol 750-752 ◽  
pp. 38-42
Author(s):  
Wang Wang Yu ◽  
Juan Li ◽  
Yun Ping Cao

In this study, the silvergrass (SV) was used to reinforce HDPE composites. The effects of polymeric methylene diphenyl diisocyanate (PMDI) content, slivergrass fibers content on the mechanical, water absortion of wood plastic composites (WPCs) were investigated. It was found that the mechanical properties of the SV reinforced HDPE composites can be improved by PMDI treatment. The highest tensile strength and flexural strength of the composites can be reached with 50% SV contents at the SV: PMDI=6:1. It has been proved that the hydroxyl groups of SV fibers which can react with the-NCO by FTIR. It also can be concluded that the water absorption of PMDI treated WPCs was lower than untreated ones.


Holzforschung ◽  
2014 ◽  
Vol 68 (8) ◽  
pp. 933-940 ◽  
Author(s):  
Yao Chen ◽  
Nicole M. Stark ◽  
Mandla A. Tshabalala ◽  
Jianmin Gao ◽  
Yongming Fan

Abstract The water sorption and mechanical properties of wood-plastic composites (WPCs) made of extracted and delignified wood flour (WF) has been investigated. WF was prepared by extraction with the solvent systems toluene/ethanol (TE), acetone/water (AW), and hot water (HW), and its delignification was conducted by means of sodium chlorite/acetic acid (AA) solution. A 24 full-factorial experimental design was employed to determine the effects of treatments and treatment combinations. WPCs were prepared with high-density polyethylene (HDPE) and treated WF was prepared by means of extrusion followed by injection molding, and the water absorption characteristics and mechanical properties of the products were evaluated. WPCs produced with extracted WF had lower water absorption rates and better mechanical properties than those made of untreated WF. WPCs containing delignified WF had higher water absorption rates and improved mechanical performance compared with those made of untreated WF.


2011 ◽  
Vol 393-395 ◽  
pp. 76-79 ◽  
Author(s):  
Hai Bing Huang ◽  
Hu Hu Du ◽  
Wei Hong Wang ◽  
Hai Gang Wang

In this article, wood-plastic composites(WPCs) were manufactured with wood flour(80~120mesh、40~80mesh、20~40mesh、10~20mesh) combing with high density polyethylene(HDPE). Effects of the size of wood flour on mechanical properies and density of composites were investigated. Results showed that particle size of wood flour had an important effect on properitiesof WPCs. Change of mesh number had a outstanding effect on flexural modulus, tensile modulus and impact strength, howere, little effect on flexural strength and tensile strength. When mesh number of wood flour changed from 80~120mesh to 10~20mesh,flexural modulus and tensile modulus were respectively enhanced by 42.4% and 28.4%, respectively, and impact strength was decreased by 35.5%.Size of wood flour basically had no effect on density of composite within 10~120mesh. The use of wood flour or fiber as fillers and reinforcements in thermoplastics has been gaining acceptance in commodity plastics applications in the past few years. WPCs are currently experiencing a dramatic increase in use. Most of them are used to produce window/door profiles,decking,railing,ang siding. Wood thermoplastic composites are manufactured by dispering wood fiber or wood flour(WF) into molten plastics to form composite materials by processing techniques such as extrusion,themoforming, and compression or injection molding[1]. WPCs have such advantages[2]:(1)With wood as filler can improve heat resistance and strength of plastic, and wood has a low cost, comparing with inorganic filler, wood has a low density. Wood as strengthen material has a great potential in improving tensile strength and flexural modulus[3];(2) For composite of same volume, composites with wood as filler have a little abrasion for equipment and can be regenerated;(3)They have a low water absorption and low hygroscopic property, They are not in need of protective waterproof paint, at the same time, composite can be dyed and painted for them own needs;(4)They are superior to wood in resistantnce to crack、leaf mold and termite aspects, composites are the same biodegradation as wood;(5)They can be processed or connected like wood;(6)They can be processed into a lots of complicated shape product by means of extrusion or molding and so on, meanwhile, they have high-efficiency raw material conversion and itself recycle utilization[4]. While there are many sucesses to report in WPCs, there are still some issues that need to be addressed before this technology will reach its full potential. This technology involves two different types of materials: one hygroscopic(biomass) and one hydrophobic(plastic), so there are issues of phase separation and compatibilization[5]. In this paper, Effects of the size of wood powder on mechanical properties of WPCs were studied.


BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 789-804
Author(s):  
Qiang Jin ◽  
Lin Zhu ◽  
Jiedeerbieke Madiniyeti ◽  
Chunxia He ◽  
Li Li

Hydration-active steel slag and slag micropowder were used as inorganic fillers with silane coupling agent (KH550) to prepare wheat straw/polyvinyl chloride wood-plastic composites (WPCs) by extrusion molding. A 35-day immersion and a pre-immersion test were carried out to analyze the influence of steel slag and slag micropowder on the physical and mechanical properties of the WPCs under wet conditions. Results showed the following: (1) KH-550 exhibited a good surface modification effect on the activated steel slag and slag micropowder, (2) an increase in the activated steel slag and slag micropowder content could effectively reduce the percent water absorption of the WPCs by 20% to 25% and the expansion by 20% to 24%, respectively, compared with the control group, but had a limited effect on the tensile strength retention, and (3) pre-immersion could effectively induce the synergistic reinforcement effect of the active fillers, resulting in reaching the saturated water absorption within 20 days. The water absorption and tensile strength were respectively 18% to 25% lower and 1.5% to 3% higher than those of the composites without pre-immersion. The results of this study could provide experimental data and theoretical references for the influence of hydration-active inorganic fillers on WPC properties.


2010 ◽  
Vol 150-151 ◽  
pp. 358-361
Author(s):  
Wen Lei ◽  
Hong Ming Ma ◽  
Yi Xu

In order to improve the flame retardancy of wood-plastic composites,a new sandwiched composite is introduced in this paper with basic magnesium sulfated whisker(MOS) filled high density polyethylene(HDPE) as skin and wood flour filled HDPE as core.The oxygen index of the skin and the mechanical properties of the whole sandwiched composite are investigated. The results show that, the flame retardancy of the skin will be improved siginicantly when much MOS is used,and the skin containing 40wt% MOS has an oxygen index of 25.6%,in addition,the sandwiched composite in which both the mass contents of MOS in the skin and wood flour in the core are 40% has better mechanical properties than the traditional wood plastic composite(WPC) without any skin,and the sandwiched WPC is more fatigue-resistant.


2014 ◽  
Vol 1004-1005 ◽  
pp. 497-500
Author(s):  
Wang Wang Yu ◽  
Dong Xue

In this study, silvergrass (SV) reinforced high density polyethylene (HDPE) composites were prepared. The effects of slivergrass fibers (SV) content on the mechanical properties, crystalline properties of wood plastic composites (WPCs) before and after water absorption were investigated. It was found that compared with the untreated WPCs after immersed into water, the tensile strength of PMDI treated composites were higher. Silvergrass can be the nucleating agent with treated by PMDI. The Xc of PMDI treated WPCs after immersed into water was also increased. However, this improved Xc has negative effect on mechanical properties.


2012 ◽  
Vol 601 ◽  
pp. 46-49
Author(s):  
Hui Zhao ◽  
Yi Long Zhou ◽  
Hong Yuan Zhu ◽  
Sheng Yuan Zhang

Ultrasonic welding technology is applied to the connection of T-type wood-plastic composites components to study its performance. The wood-plastic composite materials are made up of 60% wood-flour (WF), 36% polypropylene (PP) and 4% maleic anhydride grafted PP (MAPP). Tensile strength of the welded joint, which oscillation time is 4 seconds, is analyzed based on experimental data. Welded joint is observed by scanning electron microscope and its connection status is analyzed. Experiment results show that ultrasonic welding technology can be applied to T-type wood-plastic composites component, which has enough tensile strength.


2016 ◽  
Vol 51 (7) ◽  
pp. 955-964
Author(s):  
Yunsheng Ding ◽  
Guozhang Ni ◽  
Pei Xu ◽  
Bahader Ali ◽  
Shanzhong Yang

Wood–plastic composites were prepared from poplar wood flour and high-density polyethylene (HDPE) by melt blending and injection molding techniques, using polyethylene-grafted glycidylmethacrylate (HDPE- g-GMA) as compatibilizer and γ-aminopropyltriethoxysilane as coupling agent. The scanning electron microscopy results showed that a stronger interfacial adhesion was formed between the wood flour and HDPE matrices during the combined use of γ-aminopropyltriethoxysilane and HDPE- g-GMA, while the X-ray photoelectron spectroscopy results showed that more HDPE chains are linked to the surface of poplar wood flour through the formation of chemical bonding in the presence of γ-aminopropyltriethoxysilane and HDPE- g-GMA. So, HDPE- g-GMA and γ-aminopropyltriethoxysilane showed a synergistic effect on the improvement of compatibility between the poplar wood flour and HDPE matrices and better mechanical properties of wood–plastic composites could be obtained. Furthermore, the thermogravimetric analysis results also indicated the synergistic effects to some extent. The synergistic mechanism of γ-aminopropyltriethoxysilane and HDPE- g-GMA was proposed on the basis of investigation results.


2017 ◽  
Vol 7 (2) ◽  
pp. 1540-1545
Author(s):  
Z. Daeipour ◽  
V. Safdari ◽  
A. Nurbakhsh

Wood-plastic composites are a new group of materials that can be used in construction instead of wood and plastic. They are used in various industries due to features such as sound and water absorption, among others. This article aims to study the acoustic properties of wood-plastic composites made of wood flour, low-density polyethylene, and chalk. In this study, 6 combinations were made with different material percentages. Acoustic tests were performed for frequency ranges of 125, 250, 500, 1000, and 2000 Hz. The results of this study showed that the maximum amount of sound absorption was observed at a frequency of 2000 onwards. At the frequency of 25 to 2000, no remarkable change in sound absorption was recorded. At the 2000 to upper frequencies, one of the samples displayed the maximum amount of sound absorption. In terms of water absorption, a significant variation was reported in three samples with passing time (2, 24, 48 and 72 hours).


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