Natural durability of organomodified layered silicate filled wood flour reinforced polypropylene nanocomposites

2013 ◽  
Vol 20 (3) ◽  
pp. 227-232 ◽  
Author(s):  
Behzad Kord

AbstractThe effect of organomodified montmorillonite (OMMT) loading on the natural durability properties of polypropylene/wood flour composites exposed to brown-rot fungi (Coniophora puteana) was studied. To meet this objective, the blend composites were prepared through the melt mixing of polypropylene/wood flour at 50% weight ratios, with various amounts of OMMT (0, 3 and 6 per hundred compounds [phc]) in a hake internal mixer. The samples were then made by injection molding. The amount of coupling agent was fixed at 2 phc for all formulations. After specimen and culture medium preparation, the specimens were exposed to the purified fungus at 25°C and 75% relative humidity for 14 weeks. Identical specimens of the same composite, without being exposed to the fungus, were provided as the control specimens. After the discussed periods; weight loss, flexural strength, flexural modulus, hardness, water absorption, and thickness swelling of specimens were measured. Results indicated that OMMT had significant effects on the natural durability of the studied composite formulations. All mechanical properties were affected by the fungus, to a greater extent in the case of specimens without OMMT than the specimens with OMMT. Furthermore, the flexural strength and modulus increased with an increase of OMMT up to 3 phc and then decreased. However, the impact strength, water absorption and thickness swelling was decreased with increase of OMMT loading. Also, the lowest weight loss and the highest hardness were observed in the composite containing 6 phc organoclay. The morphology of the nanocomposites was examined by using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Morphological findings revealed that intercalation came from the sample with 3 phc concentration of OMMT, which implies the formation of intercalation morphology and better dispersion than 6 phc.

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3871-3885
Author(s):  
Amir Lashghari ◽  
Ehsan Ganjavi

This study investigated the effect of pressurized temperature on the thermal, mechanical, and morphological properties of nanocomposites made from recycled polyethylene with the weight ratio of 50%. Nanosilica was applied at 3 levels (0, 4, 8 %) and wood flour had a weight ratio of 50%. High-density polyethylene (HDPE) went through multiple procedures. It was found that by increasing the nanosilica content, the tensile and flexural strength properties, the residual ash content, and the thermal stability increased along with a reduction in the tensile and flexural modulus and impact resistance. As the temperature increased, the tensile and flexural strength and modulus and the impact resistance decreased. Scanning electron microscopy (SEM) images revealed that samples with 8% nanosilica showed different polymerization than the wood flour particles.


Resources ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 184
Author(s):  
Kati Mustonen ◽  
Ville Lahtela ◽  
Timo Kärki

The cost-efficient reutilization of byproduct materials is a significant global goal, contributing towards the sustainable use of resources. In this study, the effects of including primary sludge in composite materials on their physical performance are examined, in order to achieve more effective reuse. The studied materials were made from high-density polyethylene (HDPE), anhydride-grafted polyethylene (MAPE), lubricants, and either wood flour from spruce (Picea abies) or primary sludge from the side-stream of forest industry processes as a filler. The materials were compounded by agglomeration, followed by manufacturing with a conical twin-screw extruder. The physical properties of the materials were characterized by water absorption and thickness swelling tests; furthermore, impact strength was characterized after the stress of a cyclic freeze-thawing test. The elemental compositions of the materials were also analyzed by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). Primary sludge, as a component in the structure of the composite material, resulted in a significant improvement of moisture behaviors in the water absorption and thickness swelling tests. The identified results demonstrate that primary sludge is a technically applicable material for utilization in composite materials.


2021 ◽  
Vol 114 ◽  
pp. 70-75
Author(s):  
Radosław Auriga ◽  
Piotr Borysiuk ◽  
Alicja Auriga

An attempt to use „Tetra Pak” waste material in particleboard technology. The study investigates the effect of addition Tetra Pak waste material in the core layer on physical and mechanical properties of chipboard. Three-layer chipboards with a thickness of 16 mm and a density of 650 kg / m3 were manufactured. The share of Tetra Pak waste material in the boards was varied: 0%, 5%, 10% and 25%. The density profile was measured to determine the impact of Tetra Pak share on the density distribution. In addition, the manufactured boards were tested for strength (MOR, MOE, IB), thickness swelling and water absorption after immersion in water for 2 and 24 hours. The tests revealed that Tetra Pak share does not affect significantly the value of static bending strength and modulus of elasticity of the chipboard, but it significantly decreases IB. Also, it has been found that Tetra Pak insignificantly decreases the value of swelling and water absorption of the chipboards.


2011 ◽  
Vol 217-218 ◽  
pp. 347-352 ◽  
Author(s):  
Chun Xia He ◽  
Jun Jun Liu ◽  
Pan Fang Xue ◽  
Hong Yan Gu

The influence of the rice husks powder (RHP) content and its particle size distribution on the composite’s tensile strength, fracturing elongation ratio, flexural strength and flexural elastic modulus has been investigated. Respective water absorption and thermal properties of PP composites incorporated with different proportion of RHP have also been analyzed. The microstructure of fractured surfaces was further observed in scanning electron microscopy (SEM). The results showed that the composites with RHP of 245 μm have higher mechanical properties. The tensile strength and fracturing elongation ratio decrease with the increase of RHP content, and reach peak values in 30% RHP content. Water absorption and volume expansion ratio of the composite increase with the increasing of RHP content. Flexural strength and flexural modulus decrease after water absorption. When PHR content is low, the RHP particles are well distributed and the interface of RHP and PP is smooth. When PHR content is higher, the RHP particles tend to agglomerate, leading to poorer interface and lower mechanical properties, the composite failed with brittle fracture.


2015 ◽  
Vol 735 ◽  
pp. 3-7
Author(s):  
Aznizam Abu Bakar ◽  
Nur Azmyra Abdul Aziz ◽  
Azman Hassan ◽  
Nurhusna Azmi

The graft copolymerization was carried out under nitrogen atmosphere using the free radical initiation technique. The blend formulations were first dry blended using a mixer before being milled into sheets on a two-roll mill at 170°C, and then hot pressed into composites specimens at 175°C for 10 min. The objective of this study to investigate the mechanical and thermal properties of PVC blends. The flexural strength and modulus of ungrafted composites increased with increasing filler content from 2 to 10 part per hundred resin (phr) while the grafted composites also increased only from 2 to 6 phr filler content. The flexural modulus of ungrafted was higher compared to the grafted composites whereas the grafted showed good flexural strength than ungrafted composites. The impact strength of both composites decreased with increasing filler content but the ungrafted composites showed good toughness than grafted composites. The thermal stability of both composites increased compared to unfilled PVC.


BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3566-3584
Author(s):  
Qingde Li ◽  
Yingyi Liang ◽  
Feng Chen ◽  
Tonghui Sang

Wood fiber was modified by impulse-cyclone drying treatment with poplar and montmorillonite as reinforcing materials; mMMT/polypropylene/wood fiber foaming composite was prepared by the hot compression process. The effects of modification, temperature, and content of montmorillonite on physical and mechanical properties of the composite were analyzed. Mechanical properties, porosity, shrinkage, water absorption, and thickness swelling tests showed that when mMMT reinforcement was 5 wt%, the best performance was achieved. The scanning electron microscopy observations showed that bubble holes were distributed widely and evenly, and mMMT appeared in the cell gap and was encapsulated by polypropylene, which maximized the bonding effect. Flexural strength was 27.5 MPa, flexural modulus was 2110 MPa, tensile strength was 20.0 MPa, and impact strength was 6.30 KJ/m2. When absolute volume of dense solid reached 70.8 cm3, porosity was 21.4% and shrinkage was 1.17%, which indicated that the water absorption increased most remarkably under that test condition. When equilibrium water absorption reached 9.28%, the thickness swelling decreased by 25%. The results showed that mMMT effectively optimized mechanical properties of wood-based foamed composites and improved hygroscopic properties.


2021 ◽  
pp. 096739112110470
Author(s):  
Oluwaseun Ayotunde Alo ◽  
Iyiola Olatunji Otunniyi

Polypropylene/epoxy/synthetic graphite (PP/EP/SG) and high-density polyethylene (HDPE/EP/SG) composites were prepared by melt mixing followed by compression molding. The immiscibility of the polyolefins with epoxy was confirmed by thermogravimetric analysis. Scanning electron microscopy (SEM) studies showed that HDPE/EP blend exhibits inferior interfacial adhesion between the component polymers compared to PP/EP blend. Also, the effect of SG content on flexural properties, density, moldability, water absorption, and porosity of the PP/EP/SG and HDPE/EP/SG composites was investigated. For both PP/EP/SG and HDPE/EP/SG composites, flexural modulus, density, and porosity increased with increase in SG content. For PP/EP/SG composites, the water absorption decreased from 0.154% at 30 wt% SG to 0.072% at 70 wt% SG. Further increase in SG content to 80 wt% caused an increase in water absorption. On the other hand, water absorption for HDPE/EP/SG increased with SG content all through. At the same filler loadings, PP/EP/SG composites showed lower density and porosity and performed better in terms of flexural modulus and water absorption compared to HDPE/EP/SG composites.


2013 ◽  
Vol 834-836 ◽  
pp. 203-210 ◽  
Author(s):  
Irina Turku ◽  
Kimmo Hämäläinen ◽  
Timo Kärki

In order to improve the properties of a co-extruded wood-plastic composite (WPC), different types of cellulosic fibres, pulp cellulose (PC), a combination of PC/microfibrillated cellulose (MFC) and wood flour (WF) with different size were introduced into shell layer based on a polypropylene (PP) matrix. The combination of PC/MFC improved the tensile properties compared to PC alone; but the impact strength was independent on the MFCs content. The presence of MFCs did not influence the water absorption (WA), but thickness swelling (TS) increased, however. The properties of the WF/PP-shell composite were highly affected by the WF particle size. The 20-mesh-sized WF-loaded composite had weaker mechanical properties compared to the smaller sized, Arbocel C320, shell-layer filled WPC. Also, Arbocel C320/PP-coated WPC had the highest tensile properties among all studied composites. The morphology of the composites was examined with a scan electron microscope.


BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3427-3442
Author(s):  
Vedat Çavuş ◽  
Fatih Mengeloğlu

Neat polypropylene (PP)- and post-industrial recycled polypropylene (rPP)-based wood-plastic composites (WPC) were manufactured using 40% mahogany wood flour (WF). The effect of particle size (0.074 to 0.149 mm, 0.177 to 0.250 mm, and 0.400 to 0.841 mm) on the selected properties of PP and rPP composites was studied. The influence of 3% maleic anhydride grafted polypropylene (MAPP) presence in the formulation was also evaluated. Test specimens were manufactured using a combination of extrusion and injection molding processes. The density and mechanical properties, such as flexural strength, flexural modulus, tensile strength, tensile modulus, elongation at break, hardness and impact strength values were determined. Morphology of the manufactured composites was also studied using scanning electron microscopy (SEM) analysis. Results showed that the particle size, polypropylene type (neat or recycled), and presence of MAPP had important effects on WPC’s properties. Density, flexural modulus, tensile modulus, and impact strength values increased with decreased particle size regardless of the presence of MAPP. Flexural strength values increased with decreased particle size without MAPP. Regardless of particle size, addition of MAPP in composites provided higher flexural strength, flexural modulus, tensile strength, and tensile modulus values but lower elongation at break values compared to composites without MAPP.


2005 ◽  
Vol 6 (4) ◽  
pp. 93-100 ◽  
Author(s):  
Thomas R. Meng ◽  
Mark A. Latta

Abstract Resistance to impact fracture and high flexural strength are desirable properties of denture base acrylics. The purpose of this laboratory study was to determine the Izod impact strength, the flexural strength, the flexural modulus, and the yield distance for four premium denture resins. Bar specimens 86 x 11 x 3 mm of Lucitone 199, Fricke Hi-I, ProBase Hot, and Sledgehammer Maxipack were fabricated following the manufacturer's instructions for heat processing. The bars were surface finished using silicon carbide paper to 600 grit. Ten specimens from three lots of each material were made (n=30). Flexural strength, flexural modulus, and yield distance were determined by testing the specimens to failure using a three-point test fixture. Izod impact strength was determined using an Izod tester on un-notched specimens generated from the flexural test (n=60). Analysis of variance (ANOVA) and post-hoc Tukey's test were used for statistical comparison of each property. There were significant differences in the physical properties among the denture acrylics tested. Lucitone 199 demonstrated the highest impact strength, flexural strength, and yield distance (p<0.05). Lucitone 199 with an Izod impact strength of 5.5 ± 1.2 N·m, a flexural strength of 99.5 ± 4.5 MPa, and yield distance of 9.9 ± 0.76 mm exhibited statistically greater results than Fricki Hi-I, ProBase Hot, and Sledgehammer Maxipack. Fricki Hi- I with a yield distance of 7.3 ± 1.1 mm was statically greater than ProBase Hot and Sledgehammer Maxipack. Fricki Hi-I, ProBase Hot, and Sledgehammer Maxipack were statistically similar for the Izod impact strength and flexural strength tests performed. ProBase Hot and Sledgehammer Maxipack yielded statistically similar results for all tests performed. Flexural modulus had an inverse relationship to the impact strength, flexural strength, and yield distance. Citation Meng TR, Latta MA. Physical Properties of Four Acrylic Denture Base Resins. J Contemp Dent Pract 2005 November;(6)4:093-100.


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