Afsaneh Topa; Atamalek Ghorbanzadeh; Davood Efhamisisi
Abstract
The plasma has different effects on the surface wettability of wood, depending on the treatment conditions and the type of gas used. The hdrocarbon gases usually destroy hydrophilic groups on the surface of wood and cause hydrophobicity by creating microscopic rough structures. In this study, glide plasma ...
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The plasma has different effects on the surface wettability of wood, depending on the treatment conditions and the type of gas used. The hdrocarbon gases usually destroy hydrophilic groups on the surface of wood and cause hydrophobicity by creating microscopic rough structures. In this study, glide plasma treatment with methane was used to hydrophilize the surface of the wood and create weathering resistanc. The poplar wood (Populus deltoides) were exposed to glide plasma under various laboratory conditions such as time of exposure, voltage, frequency, distance between electrodes as well as flow of inlet gas and outlet gas with methane inside a reactor. Then the surface properties of wood were studied using scanning electron microscope (SEM), measurement of water drop contact angle, ATR‐FTIR spectroscopy, roughness survey, and colorimetry. The specimens were then subjected to the accelerated weathering using the Gardner weathering wheel and their properties were checked again. The SEM images showed that the plasma creates a warty layer on the surface of the wood which could be due to the deposition of new materials or the physical effects of plasma (surface etching). The plasma treatment significantly increased the contact angle of the water droplet on the surface of the treated samples. The treated samples had a higher surface roughness than the control samples. The surface of treated samples was generally darker than the control. After exposure to the accelerated weathering, the effect of treatments on surface hydrophobicity was largely lost. The treated samples had less roughness changes than the control after exposure to the weathering, and also their dark color changed to silver-gray. The use of glide plasma with methane gas showed the great potential for creating hydrophobic surfaces on the wood, but it did not last long and lost its effectiveness due to weathering.
Jafar Ebrahimpour Kasmani; Saeed Mahdavi
Abstract
This research was carried out with aim of the effect of nano-clay (NC) content on mechanical, thermogravimetry (TG) and morphological properties of wood plastic composite (WPC) made of medium density fiberboard (MDF) and particleboard (PB) wastes and recycled polypropylene and polyethylene (HDPE). For ...
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This research was carried out with aim of the effect of nano-clay (NC) content on mechanical, thermogravimetry (TG) and morphological properties of wood plastic composite (WPC) made of medium density fiberboard (MDF) and particleboard (PB) wastes and recycled polypropylene and polyethylene (HDPE). For this purpose, wastes of MDF and PB at 50 wt.% , recycled PP and HDPE at 50 wt.%, maleic anhydride grafted with polymers at a constant level of 3 wt.% and nanoclay at three different levels 3, 6, and 9 wt.% were blended by two-wire extruder. Afterward, standard test pieces were made using an injection molding machine and their mechanical properties and TGA were investigated. Scanning electron microscope (SEM) was applied to investigate the quality of nanoclay particles dispersion in the matrice as well as how the lignocellulosic and polymers are bonded at the surface of bonding. The results showed that tensile and flexural strength and their modulus of HDPE and PB composite significantly were increased by adding NC up to 3 wt.%, but the strengths were dropped in WPC's by increasing of NC content at 6 and 9 wt.%. The notched impact strength of WPC has been totally decreased by NC addition that indicates more fracture surface on WPC's. SEM micrographs revealed that porosity and cavities in WPC's especially were decreased at 9 wt.% NC, whereas it is clear an inappropriate dispersion and aggregation of NC in WPC. The thermal stability of WPC's was slightly improved at 3 wt.% NC and the residual after combustion increased compared to the control.
Composite wood products
Ahmad Jahan- Latibari; Roozbeh Abidnejad; Mehran Roohnia
Abstract
At this research, the influence of Multi Walled Carbon Nano Tubes (Non-functionalized and functionalized) on mechanical properties of polypropylene – old corrugated container (OCC) fibers composites was investigated. OCC fibers polypropylene composites were prepared using 20% OCC fibers, 80% polypropylene ...
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At this research, the influence of Multi Walled Carbon Nano Tubes (Non-functionalized and functionalized) on mechanical properties of polypropylene – old corrugated container (OCC) fibers composites was investigated. OCC fibers polypropylene composites were prepared using 20% OCC fibers, 80% polypropylene and 3% MAPP. Three levels of multi walled carbon nano tubes (0% - 0.5% - 1%) were added. Acidic oxidation method was used to functionalize the MWCNTs. Mechanical properties were measured as defined in ASTM testing methods. The results indicated that at higher dosage of MWCNTs, the tensile strength properties of the composite were improved but the influence of the functionalizing was not statisitaclly significant. The bending strength and elasticity as wellas the izod impact were increased as the higher amount of nanotubes were added to the composite. Scanning Electron Microscopes showed the development of bonding between the composite components. Compostes without coupling agent showed lower bonding strength between polypropylene and fiber as indicated by fiber pull out. However, in the composites containing coupling agent, the fiber fracture was observed.
Composite wood products
Hassan Ziaei Tabari; Habibollah Khademieslam; Behzad Bazyar; Amir Homan Hemmasi
Abstract
A new kind of thermoplastic elastomer nano composite reinforced with nano cellulose fibers is reported. The first aim of this investigation was to study the interaction and dispersion of nano cellulose fiber into Pebax matrix. This copolymer is Polyether – b – Amide thermoplastic elastomer ...
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A new kind of thermoplastic elastomer nano composite reinforced with nano cellulose fibers is reported. The first aim of this investigation was to study the interaction and dispersion of nano cellulose fiber into Pebax matrix. This copolymer is Polyether – b – Amide thermoplastic elastomer which is synthetized from renewable resources, and its hydrophilic character allows it to interact with nano cellulose. The interaction and reinforcement effect of nano cellulose at 3 levels of nano cellulose (1%, 3% and 5%) were examined by Scanning electron microscopes (SEM), Fourier transform infrared spectroscopy (FTIR) and Mechanical tests (young module, elongation at break and impact resistance). The results achieved from these tests were indicating appropriate effects of nano cellulose fibers for the strong interaction and close contact with polyamide phase of Pebax polymer which caused high mechanical properties (at 3% of nanoellulose) in nano composites. The young module and impact resistance of nano composite were significantly increased.
Composite wood products
Amir Nourbakhsh; Abolfazl Kargarfard
Abstract
The main objective of this research was to study the potential of bagasse fibers as reinforcement for thermoplastics as an alternative to wood fibers. The effects of three grades (Eastman G-3003, G-3015 and G-3216) of coupling agents on the mechanical properties were also studied. In the sample preparation, ...
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The main objective of this research was to study the potential of bagasse fibers as reinforcement for thermoplastics as an alternative to wood fibers. The effects of three grades (Eastman G-3003, G-3015 and G-3216) of coupling agents on the mechanical properties were also studied. In the sample preparation, one level of fiber loading (40 wt.%) and three levels of coupling agent content (0, 2 and 4 wt.%) were used. For overall trend, with addition of three grades of the coupling agents, tensile, flexural and impact properties of the composites significantly improved, as compared with untreated samples. In addition, morphological study (SEM) revealed that the positive effect of coupling agent on interfacial bonding. The composites treated with G-3216 gave better results in comparison with G-3003 and G-3015 in which, There are some voids where the fibers have been pulled-out. The presence of these voids means that the interfacial bonding between the fiber and the matrix polymer is weak. This could be caused by the high melt viscosity of G-3216 Coupling agent.
Pulp and paper
Moghadaseh Akbari; Nadia Kabodi torabi; Hossein Rrsalati; Gasem Asadpour atoei; Mohammad reza Dehghani firozabadi
Abstract
Aim of this study is precipitated calcium carbonate cationic modification and comparison of impact of using its with conventional filler (unmodified) on strength properties of paper. One of the defects of adding fillers to paper is decreasing of mechanical strength of paper because of reduction in bonding ...
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Aim of this study is precipitated calcium carbonate cationic modification and comparison of impact of using its with conventional filler (unmodified) on strength properties of paper. One of the defects of adding fillers to paper is decreasing of mechanical strength of paper because of reduction in bonding area between fibers. In this study whit purpose of maintaining the strength of paper, and change the surface charge of precipitated calcium carbonate and replace it with conventional fillers are used.in this research with aim of precipitated calcium carbonate and replacing it with conventional filler was used. Condition of cationic precipitated calcium carbonate preparation was 90 ċ temperature, 3 hours time and 55% water content of cooking process. loading amount of starch was 9, 12 and 15 percent based on precipitated calcium carbonate weight.Papers made at three level: 10, 16, 30 percent of filler in paper sheets contain conventional fillers were compared. Results indicated that papers containing modified-filler have more values of retention rather than those with unmodified filler, both in 20% and 30% filler dosages.papers contained cationic filler have more mechanical strength index in respect of papers contained conventional fillers.
Amir Nourbakgsh
Abstract
Two recycled polymers (rHTPE and rPP) combined with baggase fibers were used as the reinforcing material to improve the mechanical properties of wood plastic nanoclay composite. The amount of baggase fibers varied at three levels (25, 35 and, 45 percent). Two recycled polymers (rPP and rHDPE) were used ...
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Two recycled polymers (rHTPE and rPP) combined with baggase fibers were used as the reinforcing material to improve the mechanical properties of wood plastic nanoclay composite. The amount of baggase fibers varied at three levels (25, 35 and, 45 percent). Two recycled polymers (rPP and rHDPE) were used as polymer matrix. Tensile, flexural and impact strength properties were measured according to ASTM standard tests. Scanning electron microscopy (SEM) and X-Ray Diffraction (XRD) was performed to interpret the results. The results were statistically analyzed using factorial experimental under completely randomized block design and the averages were compared using DMRT. The application of 35 percent bagasse fibers as compared with 25 and 45 percent increased the strength of wood plastics composites. However, higher impact strength was reached using 25% bagasse fibers as compared with either 35 or 45% bagasse fibers. rHDPE nano-clay composite showed higher tensile, flexural and impact properties compared with rPP. Imaging the morphology of nano-clay by X-Ray diffraction and scanning electron microscopy showed the distribution of nano-clay particles in polymer structure and intercalation was observed.
