The effect of alkaline–silane treatment of rubberwood flour for water absorption and mechanical properties of plastic composites

2018 ◽  
Vol 33 (5) ◽  
pp. 599-613 ◽  
Author(s):  
Sriwan Khamtree ◽  
Thanate Ratanawilai ◽  
Sukritthira Ratanawilai

Rubberwood flour (RWF) was treated by alkaline, silane, and alkaline–silane, and consequently, reinforced recycled polypropylene (rPP) composites. The wood–plastic composites (WPCs) were prepared with 40 wt% RWF content using a twin-screw extruder, followed by compression molding. Silane treatment was applied at various concentrations and treatment times to evaluate the effect of treatment conditions on water absorption, mechanical properties, thermal properties, and morphological characterization of WPCs. The results indicated that alkaline–silane treatment of RWF exhibits higher properties in comparison to silane or alkaline only. In addition, silane concentrations significantly affected water absorption, mechanical strength, and hardness, while treatment times remained relatively unaffected by these properties. The best water resistance, mechanical strength, and hardness of WPCs were achieved by alkaline–silane treatment with 5% silane concentration for 2 h, which improved the interfacial adhesion of RWF and rPP as well as increased the crystallinity in the WPCs.

2010 ◽  
Vol 660-661 ◽  
pp. 681-685
Author(s):  
Carlos Maurício Fontes Vieira ◽  
Lussandra Arêdes Freitas ◽  
Rubén Jesus Sánchez Rodríguez ◽  
Sérgio Neves Monteiro

This work has as its objective to evaluate the effect in the physical and mechanical properties of a red ceramic by the incorporation of petroleum coke from a refining plant. The characterization of the coke was done by optical microscopy and DTA/TG. Compositions were prepared with 0, 1, 2 and 4 wt.% of petroleum coke incorporated into a kaolinitic clayey body. Rectangular specimens were formed by extrusion before firing at 950°C. The determined physical and mechanical properties were: flexural rupture strength and water absorption. The microstructure of the fired ceramics was evaluated by SEM. The results showed that the incorporation of up to 4 wt.% of petroleum coke is not deleterious to the water absorption and mechanical strength of the clayey ceramic fired at 950oC.


Author(s):  
Ênio Henrique Pires da Silva ◽  
Emiliano Barretto Almendro ◽  
Amanda Albertin Xavier da Silva ◽  
Guilherme Waldow ◽  
Flaminio CP Sales ◽  
...  

Composites using natural fibers as reinforcement and biodegradable polymers as matrix are considered environmentally friendly materials. This paper seeks the mechanical and morphological characterization of a biocomposite of polyurethane (PU) derived from a blend of vegetable oils doped with aluminatrihydrate (ATH) and reinforced with hydrated cotton fiber fabric (HCF). The comparison and study were performed based on the properties of the: (i) pure PU; (ii) PU doped with ATH containing 30% of the final mass (PU+30%ATH); (iii) composite of PU reinforced with 7 layers of cotton fiber fabric (PU+7CF); (iv) composite of PU+30%ATH reinforced with 7 layers of CF (PU+30%ATH+7CF); (v) composite of PU+30%ATH reinforced with 7 layers of hydrated cotton fiber fabric (PU+30%ATH+7HCF). The mechanical properties obtained according to the tensile test for the composite PU+30%ATH+CF with fibers oriented at 0° showed a significant increment in tensile strength (60 MPa) and the modulus of elasticity (4.7 GPa) when compared to pure PU (40 MPa) and (1.7 GPa) respectively. PU+30%ATH also presented a rising tensile strength (31 MPa) and Young modulus (2.6 GPa). For the composite with addition of water, results presented a significant decrease in strength (31.3 MPa) and stiffness (0.9 GPa) than the composite with no water. Electron microscopy (SEM) analyses exhibited that the samples with addition of water showed the presence of large amounts of pores and the lower interaction between matrix and fiber. These results may explain the lower mechanical properties of this material. DOI: http://dx.doi.org/10.30609/JETI.2019-7576


Natural fibers from plants are gaining importance and may substitute wood in the production of wood plastic composites (WPC). To ensure continuity of fiber supply and sustainability of WPC industries, fibers of various types could be mixed together to obtain Mix WPC. However, research need to be carried out to identify the contribution of different fiber type collectively to the mechanical properties of Mix natural fiber polymer composite (NFPC). In this study, preliminary work on the use of natural fibre (NF) such as kenaf, sugar palm and pineapple leaf fibers in the preparation of Mix NFPC were carried out. Four different fiber mix samples with different fiber ratio and size were formulated using polypropylene (PP) as the polymer matrix. Montmorrilonite (MMT) filler was added at constant amount for enhancement of composite mechanical properties. Samples were mixed and prepared using a twin screw extruder and mini injection moulding resepectively. Individual fibers and NFPC prepared were characterized using thermogravimetric analyzer (TGA). Tensile, flexural and impact strength of the composites were determined. Generally, it was found that addition of fiber mix at 50% fiber loading enhance the tensile and flexural strength of the various NFPC with minimal exceptions. The impact strength of the composites were comparable to that of blank PP implying that addition of fiber gives additional advantage besides being eco-friendly. It was also found that higher kenaf loading and different size of fiber mix contribute positively to the various strengths measured. In addition to that, composition of individual fibers also contribute to the mechanical properties of the NFPCs


2010 ◽  
Vol 152-153 ◽  
pp. 1650-1659
Author(s):  
Qing Hao Yang ◽  
Guang Xu Cheng ◽  
Zhi Cheng Zhang

In an effort to seek poly(vinyl formal) (PVFM) foams based wound dressing pad material, a series of foamed PVFM materials have been synthesized under varied conditions. The influence of conditions on the properties of PVFM foam, such as mechanical properties, water absorption, pore structure and bulk density, is well discussed individually. It has been shown that both the reactant and acid catalyst affect the degree and speed of acetalization, therefore the mechanical properties, pores continuity and water absorption of the resultant sample. The addition of Na2CO3, surfactant and CMCNa are mainly influencing the porous structure as well as the mechanical properties and water absorption. One best sample with balanced properties is obtained. It possesses higher mechanical strength and water absorption while the other properties are similar, comparing with a commercial surgical PVFM sponge (YJ-1) currently used.


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.


2012 ◽  
Vol 724 ◽  
pp. 249-254 ◽  
Author(s):  
Bum Rae Cho ◽  
Ji Hoon Chae ◽  
Bo Lang Kim ◽  
Jong Bong Kang

Sintered ZTA(zirconia toughened alumina) which has good mechanical properties at a low temperature was produced by milling and mixing with Al2O3 and ZrO2(3Y-TZP). In order to examine the effect of sintering aids on the mechanical properties of ZTA, fracture toughness and hardness of the produced ZTA were observed in accordance with change of the added quantity of ZrO2 Scanning electron microscopy and X-ray diffraction technique were applied to observe microstructural change and phase transformation during the process. Experimental results showed that the addition of sintering aids in ZTA at a low temperature induced densification and adding SiO2 and talc lowered sintering temperature and promoted crystallization process of the compound. The mechanical strength of ZTA added ZrO2 showed higher mechanical strength and SEM analysis revealed that Al2O3 and ZrO2 during the sintering process restrained the grain growth each other. Especially, the 92% Al2O3 added sintering aids showed more than 98% of the theoretical density and more than 1500 Hv of hardness value at a low temperature of 1400. It was also showed that the fracture toughness is gradually increasing first and decreasing later in accordance with the quantity of ZrO2.


Clay Minerals ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 195-205 ◽  
Author(s):  
Y. Zhu ◽  
G. C. Allen ◽  
J. M. Adams ◽  
D. Gittins ◽  
P. J. Heard ◽  
...  

AbstractTwo types of mineral fillers, talc and mica, were compounded into polypropylene (PP) via a twin-screw extruder. The morphologies and mechanical properties of the resultant composites were investigated. The dispersion of minerals in PP was observed using Focused Ion Beam (FIB) techniques. The particle size distribution (PSD) and aspect ratio (AR) of particles in the polymer phase were obtained from FIB image analysis. It was found that FIB imaging displays directly the micron to mesoscale level dispersion of particles in polymeric composites. The technique has significant potential for characterizing such materials, having some advantages over ‘traditional’ scanning and transmission electron microscopy in terms of generating representative data in a realistic timescale. The PSD and AR distribution and degree of dispersion in the composites give insights into the modification of mechanical properties of the composites studied.


2013 ◽  
Vol 197 ◽  
pp. 186-191 ◽  
Author(s):  
Aneta Gądek-Moszczak ◽  
Sabina Żmudka

The main goal of the study was working out the method of qualitative and quantitative analysis of the microstructure on 3D images of the polypropylene composites with Tuf (type of rock consisting volcanic ash) particles. Three types of composite were analyzed: with 10, 15 and 25% of Tuf. The standard morphological parameters were indicated that describes size, shape, and distribution of Tuf particles in the matrix. The morphological characterization of examined microstructure was compared with mechanical properties. The optimal from the point of mechanical properties composition of this composite were proposed.


2016 ◽  
Vol 723 ◽  
pp. 56-61 ◽  
Author(s):  
Zheng Hao Ge ◽  
Dan Ge Si ◽  
Yun Li Lan ◽  
Mei Nong Shi

Though there has been a large number of studies concerning the modification of wood plastic composite materials, there is still more to be done. This report aims to study the effect of the coupling agents (PP-g-MAH, silane, titanate) and compatibilizer(SBS) on the mechanical properties of straw flour/waste plastic composites. Straw flour, waste plastic, modifying agents and other additives were mixed evenly in a high speed mixing machine. And the mixed materials were compounded into the pelllets using the twin-screw extruder. Then the test specimens were prepared by the injection molding. The influence of 4% coupling agent (PP-g-MAH, silane, titanate) on the mechanical properties of straw flour/waste plastic composites was researched, and the most suitable coupling agent to the composites was obtained. In order to increase the toughness of the composite materials and to furthermore improve the comprehensive mechanical properties, the WPCs with different contents styrene butadiene styrene (SBS) were investigated. The experimental results showed that the coupling agent PP-g-MAH and the content was 4%, the mechanical properties of the composite materials were better; when SBS content was 5%, the maximum increases of tensile strength, flexural strength and impact strength of SBS modified WPCs were by 14.34%, 20.75%, 34.38% compared to those of neat WPCs respectively.


Author(s):  
ANDRÉS PACHECO LANCHEROS ◽  
AURA LOMBANA PUERTA ◽  
ÁLVARO REALPE JIMÉNEZ ◽  
DINA MENDOZA BELTRAN ◽  
MARÍA TERESA ACEVEDO MORANTES

Proton Exchange Membranes (PEMs) are materials developed with a focus on high-performance, low-cost features to achieve promising fuel cell technology in stationary, portable, and transportation facilities. In this study, we synthesized membranes from Poly (oxy-1,4-phenylenesulfonyl-1,4-phenylene) (PES) sulfonated with modification by adding nanoclay to improve the mechanical properties of PEMs. The sulfonation time and the concentration of nanoclays directly favored properties such as contact angle, water absorption, porosity, and mechanical properties. However, a higher concentration of nanoclays (e.g., 10% by weight) damages the mechanical properties of PES membranes specifically. The membrane with 5% by weight of nanoclay and a sulfonation time of 2 h achieved the best performance.


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