Study on Application of Modified Polyethylene in Preparation of Wood-Plastic Composites

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%).

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.


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.


2011 ◽  
Vol 236-238 ◽  
pp. 1725-1730 ◽  
Author(s):  
Wei Jen Chen ◽  
Ming Yuan Shen ◽  
Yi Luen Li ◽  
Chin Lung Chiang ◽  
Ming Chuen Yip

This study used carbon aerogels (CA) and phenolic resin in fixed proportations to produce nano high polymer resin, and used poly ehtylene oxide (PEO) as the modifying agent for phenolic resin to improve the mechanical properties of phenolic resin and promote the surface conductivity. The prepared nano high polymer resin and carbon cloth were made into nano-prepreg by using ultrasonic impregnation method, and a nano-prepreg composite material was prepared by using hot compacting and cut to test pieces to measure its mechanical properties and surface conductivity as well as the influence of temperature-humidity environment (85°C/168hr and 85°C/85%RH/168hr) on mechanical properties. The result showed that the surface conductivity increased by 64.55%, the tensile strength at room temperature increased by 35.7%, the flexural strength increased by 18.4%, and the impact strength increased by 101%. In hot environment (85°C/168hr), the tensile strength decreased by 23.8%, the flexural strength increased by 3.1%, and the impact strength increased by 84.6%. In high temperature-high humidity environment (85°C/85% RH/168hr), the tensile strength decreased by 29.6%, the flexural strength decreased by 17%, and the impact strength increased by 95.7%.Introduction


2013 ◽  
Vol 747 ◽  
pp. 355-358 ◽  
Author(s):  
Pornsri Pakeyangkoon ◽  
Benjawan Ploydee

Mechanical properties of wood plastic composite, prepared from acrylate-styrene-acrylonitrile (ASA) and bagasse, were investigated. In this study, 10 to 50 phr of bagasse were used in order to obtain the wood plastic composite with superior mechanical properties. The wood plastic composites in the study were prepared by melt-blending technique. All materials were mixed by using a two-roll-mill, shaped into sheets by a compression molding machine and the specimens were cut with a cutting machine. Youngs modulus, flexural strength, flexural modulus, impact strength and hardness of the wood plastic composites were investigated and found to improve with increasing bagasse content. However, some composite properties, i.e., impact strength, was decreased by adding the bagasse and then become steady when the amount of bagasse added was more than 30 phr. It was concluded that wood plastic composites with the desirable mechanical properties can be formulated using ASA as the matrix polymer and 50 phr of bagasse.


2011 ◽  
Vol 378-379 ◽  
pp. 735-739
Author(s):  
Yue Wen Li ◽  
Xin Hua Chen

Reactive compatibilization between high-density polyethylene(HDPE) and wood-flour was achieved via direct reactive extrusion of glycidyl methacrylate(GMA), initiator, HDPE and wood-flour. Impact rupture surface of the composite was observed by scanning electron microscope(SEM), and its load deformation temperature(HDT) and mechanical properties were tested. Effect of GMA dosage and extrusion temperature on reactive compatibilization of the composite was analysed. The result indicated that the anchoring strength of interface in the composite was obviously strengthened, and its HDT, tensile strength, flexural strength, notched impact strength and elongation at break of the composite were distinctly improved due to the addition of GMA and dicumyl peroxide(DCP). When the composite was extruded at 180°C, the peak values of its HDT, tensile strength, flexural strength, elongation at break and notched impact strength respectively were 84°C, 40Mpa, 45Mpa, 11% and 6.6KJ.m-2, which respectively increased by 17°C, 74%, 36%, 83% and 69% than that of the composite without reactive compatibilization, and when the composite was extruded at 190°C, the peak values of its HDT, tensile strength, flexural strength, elongation at break and notched impact strength respectively were 84°C, 40Mpa, 44Mpa, 11% and 6.6KJ.m-2, which respectively increased by 20°C, 60%, 26%, 83% and 83% than that of the composite without reactive compatibilization. When GMA usage increased, the HDT and mechanical properties of the composite increased first, then descended, and the optimum usage of GMA was 1wt%-3wt%.


2015 ◽  
Vol 1094 ◽  
pp. 105-108
Author(s):  
Hong Li Jiang ◽  
Jing Lun Zhou ◽  
Jian Dong ◽  
Yu Min Wang ◽  
Jiu Yong Ruan

The wood flour/HDPE microcellular foamed composites were prepared by means of torque rheometer. The effect of different wood flour content on mechanical properties and foamed behavior were studied. Results showed that the tensile strength and flexural strength of microcellular foamed composites first increased then decreased and the notched impact strength decreased with addition of wood flour, this was consistent with non-foamed composites. The density of composites increased and the density of foamed composites was less than non-foamed composites. With increasing wood flour content, the cell diameter of foamed composites first decreased then increased. When the content of wood flour was 40%, the cell diameter of the composites obtained the minimal value.


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.


2016 ◽  
Vol 36 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Ayyanar Athijayamani ◽  
Balasubramaniam Stalin ◽  
Susaiyappan Sidhardhan ◽  
Azeez Batcha Alavudeen

Abstract The present study describes the preparation of aligned unidirectional bagasse fiber-reinforced vinyl ester (BFRVE) composites and their mechanical properties such as tensile, flexural, shear and impact strength. Composites were prepared by a hand lay-up technique developed in our laboratory with the help of a hot press. Mechanical properties were obtained for different fiber contents by varying the number of layers. The obtained tensile property values were compared with the theoretical results. The results show that the tensile strength increased linearly up to 44 wt% and then dropped. However, the tensile modulus increased linearly from 17 wt% to 60 wt%. In the case of flexural properties, the flexural strength increased up to 53 wt% and started to decrease. However, the flexural modulus also increased linearly up to 60 wt%. The impact strength values were higher than the matrix materials for all the specimens. The short beam shear strength values were also increased up to 53 wt% and then dropped. The modified Bowyer and Bader (MBB) model followed by the Hirsch model shows a very good agreement with experimental results in both tensile strength and modulus.


2007 ◽  
Vol 15 (5) ◽  
pp. 365-370 ◽  
Author(s):  
L.M. Matuana ◽  
S. Cam ◽  
K.B. Yuhasz ◽  
Q.J. Armstrong

This study examined both the use of acrylonitrile-butadiene-styrene (ABS) as a plastic matrix for wood-plastic composites (WPCs) and the effect of impact modification on the mechanical properties of ABS/wood-flour composites. Blends of ABS filled with wood flour (both pine and maple) were processed into profile shape using a conical twin-screw extruder and the mechanical properties of the resulting composites were characterised and compared to WPCs made with polyolefins (HDPE and PP) and rigid PVC matrices. Generally, WPCs made with ABS matrix outperformed their polyolefin counterparts in both flexural strength and modulus, whereas ABS-based composites had inferior strength but greater modulus than those made with rigid PVC. The impact strength of ABS/wood-flour composites was below that of wood plastic composites made with polyolefins. However, impact modification with acrylonitrile-butadiene-styrene terpolymers had some effect in toughening of the ABS/wood-flour composites.


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