Mohamad Bai; Behzad Bazyar; Habibollah Khademi Eslam; Abdolah Najafi; Amir Hooman Hemasi
Abstract
In this study, the effect of cellulose nanofibers and silicon nanoparticles on the properties of nanocomposites made with polyvinyl alcohol was studied and the physical, mechanical and morphological properties of nanocomposites were investigated. Samples were prepared by casting with different ratios ...
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In this study, the effect of cellulose nanofibers and silicon nanoparticles on the properties of nanocomposites made with polyvinyl alcohol was studied and the physical, mechanical and morphological properties of nanocomposites were investigated. Samples were prepared by casting with different ratios of 0, 5 and 10% by weight. The morphology of nanocomposites was examined by scanning electron microscopy. Observations of water vapor permeability and water uptake by adding cellulose and nanoxide oxide nanofibers in pure polyvinyl alcohol control film and nanocomposite films with different compositions were significantly different from each other. Tensile strength of nanocomposites showed that increasing the amount of cellulose nanofibers and silicon nanoparticles increased the tensile strength and the percentage of elongation increased with the addition of cellulose nanofibers and silicon nanoparticles decreased. The results of the present study show that the addition of small amounts of nanocellulose fibers and silicon nanoparticles strengthens the polyvinyl alcohol polymer and improves the physical and mechanical properties and increases the performance of nanocomposites.
Pulp and paper
Alireza Khakifiroz; Seeyed Ahmad Mirshokraie; Amir homman Hamasi; Hababalah Khadmieslam; Mohammad Talaei poor
Abstract
Permanent or durable paper is a kind of paper that has a high degree of permanence and is likely to retain the properties which influence readability and document handling when storing in a protected environment for a long period. Permanence depends mainly on the chemical stability of the paper itself. ...
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Permanent or durable paper is a kind of paper that has a high degree of permanence and is likely to retain the properties which influence readability and document handling when storing in a protected environment for a long period. Permanence depends mainly on the chemical stability of the paper itself. Stability may be impaired by chemical reactions involving the paper's own components and by reactive agents from the environment and human being i.e., from air or filing enclosures. Poor chemical stability produces a chain reaction which in long term storage has a pronounced adverse effect on the mechanical or optical properties of the document. The main reactions causing mechanical deterioration are acid hydrolysis and oxidation. Yellowing is due to photochemical and thermal processes. Whatever the fibers used to make paper are longer , alkaline paper making is used , cationic elements such as Fe+2, Fe+3, Cu+2, Mn+2 and kappa number of pulp are minor, it is expected that the paper made is more permanent .In this research imported bleached Eucalyptus kraft pulp was used. The used pulp was refined according to tappi test method T248 cm-85 with PFI mill to reach freeness (300±25) CSF at number of beating revolutions 12000 .Hand sheets were made according to SCAN C25-65 standard with grammage 70.AKD sizing were used 2% oven dry weight of pulp and EDTA as chelating agent was used in concentrations 0 , 0.25 , 0.5 , 0.75 percent. For more assurance deionized water was used. furthermore, 20% calcium carbonate was used as residual alkaline and filler. Then hand sheets were laid under U.V radiation with wavelengths between 330 to 440 nm in 0,10, 20, 30, 40 and 50 hours interval and were conditioned in controlled temperature and relative humidity . pH of Extractive solutions were adjusted between 7 to 7.5 . At last, each strength indices were measured with three measurement frequencies and to compare the amount of mean strengths of produced handsheets, variation analysis (ANOVA) and Duncan test were used with SPSS software and the charts were drawn with Excel software.
Composite wood products
Reza Jazayeri; Habib alah Khademi eslam; Amir Nourbakhsh; Abolfazl Kargarfard
Abstract
In order to survey of possibility of particle board production with «Acacia salicina » the effectiveness of three factor (treatment) included adhesive percentage (in two surface: %9 and %11) temperature degree ( in two surface 1650c and 1750c) pressing time (in three surface: 5/6 and 7 minutes) ...
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In order to survey of possibility of particle board production with «Acacia salicina » the effectiveness of three factor (treatment) included adhesive percentage (in two surface: %9 and %11) temperature degree ( in two surface 1650c and 1750c) pressing time (in three surface: 5/6 and 7 minutes) on mechanical (MOR, MOE, IB) and physical (TS2, TS24) properties were experimented with E.N standard. Therefore 36 boards were prepared for mechanical and physical tests. Data were analyzed with appropriated statistical method. Results indicate %11 adhesive, 1650c temperature degrees and 6 minutes press time is best condition for production. However the results showed more than standard IB (1/24 Mpa ) probably due to its wood chemistry. Therefore this species could be a suitable source to produce particle board
Composite wood products
Abdolah Najafi; Mehdi Faezipoor; Habibalah Khademi eslam; Saeid Kazemi; Amir homan Hamasi
Abstract
In this study flexural properties Wood-plastic composites(WPCs), the composites made from high density polyethylene(virgin, recycled and mix of them) and four types lignocellulosic fillers (wood sawdust, sanding of MDF, particleboard sawdust and rice hull) at %60 by weight fiber loadings were manufactured ...
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In this study flexural properties Wood-plastic composites(WPCs), the composites made from high density polyethylene(virgin, recycled and mix of them) and four types lignocellulosic fillers (wood sawdust, sanding of MDF, particleboard sawdust and rice hull) at %60 by weight fiber loadings were manufactured using a dry blend/hot press method. Nominal density and dimensions of the panels were 1g/cm3 and 35Î35Î1cm, respectively. After conditioning, flexural properties of the panels including flexural modulus and flexural strength were determined. The results show the flexural modulus and strength wood plastic composites containing sanding MDF and particleboard sawdust were higher than those made from other fillers. The flexural modulus and strength were affected by kind of high density polyethylene (virgin or recycled
