Preparation and Properties of Wood Flour/HDPE Microcellular Foamed Composites

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.

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%.


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%).


2014 ◽  
Vol 1025-1026 ◽  
pp. 215-220 ◽  
Author(s):  
Sasirada Weerasunthorn ◽  
Pranut Potiyaraj

Fumed silica particles (SiO2) were directly added into poly (butylene succinate) (PBS) by melt mixing process. The effects of amount of fumed silica particles on mechanical properties of PBS/fumed silica composites, those are tensile strength, tensile modulus, impact strength as well as flexural strength, were investigated. It was found that the mechanical properties decreased with increasing fumed silica loading (0-3 wt%). In order to increase polymer-filler interaction, fumed silica was treated with 3-glycidyloxypropyl trimethoxysilane (GPMS), and its structure was analyzed by FT-IR spectrophotometry. The PBS/modified was found to possess better tensile strength, tensile modulus, impact strength and flexural strength that those of PBS/fumed silica composites.


2021 ◽  
Vol 887 ◽  
pp. 110-115
Author(s):  
G.A. Sabirova ◽  
R.R. Safin ◽  
N.R. Galyavetdinov

This paper presents the findings of experimental studies of the physical and mechanical properties of wood-filled composites based on polylactide (PLA) and vegetable filler in the form of wood flour (WF) thermally modified at 200-240 °C. It also reveals the dependence of the tensile strength, impact strength, bending elastic modulus, and density of composites on the amount of wood filler and the temperature of its thermal pre-modification. We established that an increase in the concentration of the introduced filler and the degree of its heat treatment results in a decrease of the tensile strength, impact strength and density of composite materials, while with a lower binder content, thermal modification at 200 °C has a positive effect on bending elastic modulus. We also found that 40 % content of a wood filler heated to 200 °C is sufficient to maintain relatively high physical and mechanical properties of composite materials. With a higher content of a wood filler, the cost can be reduced but the quality of products made of this material may significantly deteriorate. However, depending on the application and the life cycle of this product, it is possible to develop a formulation that includes a high concentration of filler.


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


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.


Author(s):  
Mostafa Hassani Niaki ◽  
Morteza Ghorbanzadeh Ahangari ◽  
Abdolhossein Fereidoon

This paper studies the mechanical properties of polymer concrete (PC) with three types of resin systems. First, the effect of 0.5 wt% up to 3 wt% basalt fiber on the mechanical properties of a quaternary epoxy-based PC is investigated experimentally, and the best weight percentage of basalt fiber is obtained. The results show that adding basalt fiber to PC caused the greatest enhancement within 10% in compressive strength, 10% in flexural strength, 35% in the splitting tensile strength, and 315% in impact strength. In the next step, the effect of nanoclay particles on the mechanical properties of basalt fiber-reinforced PC (BFRPC) is analyzed experimentally. Nanoclays increase the compressive strength up to 7%, flexural strength up to 27%, and impact strength up to 260% but decrease the tensile strength of the PC. Field-emission scanning electron microscopy (FESEM) analysis is performed to study the fracture surface and morphology of various concrete specimens. In the last step, we consider the effect of two other different resin systems, rigid polyurethane and rigid polyurethane foam on the mechanical properties of reinforced polymer concrete. A comparison study presents that the epoxy PC has a higher specific strength than the polyurethane and ultra-lightweight polyurethane foam PC.


2019 ◽  
Vol 38 (5-6) ◽  
pp. 111-130
Author(s):  
Guiwei Dong ◽  
Guoqun Zhao ◽  
Junji Hou ◽  
Guilong Wang ◽  
Yue Mu

In this work, the effects of dynamic mold temperature control (DMTC) on melt pressure, cellular structure, and mechanical properties of microcellular injection molding (MIM)-molded parts are investigated experimentally. It is found that with the increase of the mold temperature, the duration of foaming pressure in the cooling stage increases. Meanwhile, the average cell diameter and cell diameter dispersion increases as well as the cell density decreases in MIM molded parts. The turning point of mold temperature after which the foaming pressure in the cooling stage and the cellular structure in MIM molded parts generate a significant change is around the glass transition temperature of the used plastic material. Under DMTC conditions, with the increase of mold temperature, the tensile strength, flexural strength, and impact strength of MIM molded specimens of single gate without weld line change a little, while the tensile strength, flexural strength of MIM molded specimens of double gates with weld line increase obviously. When the mold temperature increases to 120°C and over, the tensile strength, flexural strength of MIM molded specimens of double gates with weld line reach an equivalent level of specimens of single gate without weld line.


2011 ◽  
Vol 24 (6) ◽  
pp. 735-754 ◽  
Author(s):  
Z. Xiuju ◽  
S. Juncai ◽  
Y. Huajun ◽  
L. Zhidan ◽  
T. Shaozao

Polypropylene (PP)/microcrystalline cellulose (MCC) composites and PP/MCC composites modified by maleic anhydride grafted PP (PP-g-MA) and methyl acrylic acid glycidyl ester grafted PP (PP-g-GMA) respectively were prepared in a twin-screw extruder. The mechanical properties, morphology, and thermal performance were investigated. The nonisothermal crystallization, melting behavior, and nonisothermal crystallization kinetics were investigated by DSC. The results indicated that the addition of MCC had led to the increase of the tensile strength, impact strength, and flexural strength of PP. PP-g-GMA modification was more conducive to the improvement in tensile strength, impact strength, and flexural strength. The three types of PP/MCC composites have higher thermal decomposition temperatures, Vicat softening temperatures, and dimensional stability. Nonisothermal crystallizations of PP/MCC composites were in accordance with tridimensional growth with heterogeneous nucleation. Meanwhile, MCC was acted as the nucleating agent in PP matrix, which increased the crystallization temperature. PP-g-GMA further increased the crystallization temperature while PP-g-MA weakened the heterogeneous nucleation effect of MCC. Avrami equation and Mo method give a satisfactory description of the crystallization kinetics process. The activation energy of crystallization, nucleation constant, and fold surface free energy of PP were markedly reduced in PP/MCC composites and its compatibilized composites. The value of F( T) systematically increased with increasing relative degree of crystallinity. The addition of microcrystalline cellulose has greatly reduced the spherulitic size of PP.


2015 ◽  
Vol 12 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Abhishek Suvarna ◽  
Akash Katagi ◽  
Jackson Pasanna ◽  
Sunil Kumar ◽  
Basavaraju Bennehalli ◽  
...  

The present investigation focuses on the fabrication and mechanical characterization of alkali treated natural abaca fiber reinforced urea formaldehyde composites. The composites were prepared by means of compression moulding, and then the effects of fiber loading on mechanical properties such as tensile strength, flexural strength and impact strength were investigated. The composite with 40 wt% abaca fibers gave excellent tensile strength and flexural strength showing that it has the most superior bonding and adhesion of all the composites. In particular, the highest value, 10.02 kJ/m2 of charpy impact strength is observed in the composite with 50 wt% abaca fiber. This work revealed the potential of using abaca fibers in fiberboard.


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