Mohammad Reza topa esfandiyari; Mohammad Talaei poor; Habibollah Khademi Eslam; Seeyed Ahmad Mirshokraie; behzad baziyar
Abstract
This study uses soda lignin to modify it with furfural as adhesive on the physical and mechanical properties of plywood Poplar wood. Producing plywood, pure Lignin (L.100%), lignin-furfural 30% (L.70-F.30), lignin- furfural 60% (L.40-F.60) were used as the adhesive at three different levels ( 120 140 ...
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This study uses soda lignin to modify it with furfural as adhesive on the physical and mechanical properties of plywood Poplar wood. Producing plywood, pure Lignin (L.100%), lignin-furfural 30% (L.70-F.30), lignin- furfural 60% (L.40-F.60) were used as the adhesive at three different levels ( 120 140 160gm2) accompanied with ammonium chloride (1%) as the hardener and wheat flour (30%) as the filler based on the dry weight of the adhesive. Plates made with urea formaldehyde resin at 160 g/m2 were produced as control samples. characteristics of adhesives included solid material percentage, viscosity, specific weight and PH were measured. After producing the laboratory boards, the physical and mechanical properties of samples, such as thickness swelling after 2 and 24 hours of being soaked in water, shear strength, modulus of rupture, and modulus of elasticity were measured. The results indicate that independent and interactive effects of adhesive and its consumption level on the physical and mechanical properties of plywood are not statistically significant. And in all cases, the control boards had better properties than the lignin adhesives
Mohammad Reza topa esfandiyari; Mohammad Talaei poor; Habibollah Khademi Eslam; Seeyed Ahmad Mirshokraie; Behzad Bazyar
Abstract
This study uses the Lignin-Glyoxal adhesive to replace chemical resins with environmental compounds producing plywood. producing plywood, pure Lignin (L.100%), lignin- glyoxal 15% (L.85-G.15), lignin-glyoxal 30% (L.70-G.30) and Urea-formaldehyde (control) were used as adhesive at 160 gr/m2 level. Accompanied ...
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This study uses the Lignin-Glyoxal adhesive to replace chemical resins with environmental compounds producing plywood. producing plywood, pure Lignin (L.100%), lignin- glyoxal 15% (L.85-G.15), lignin-glyoxal 30% (L.70-G.30) and Urea-formaldehyde (control) were used as adhesive at 160 gr/m2 level. Accompanied with ammonium chloride (1%) as the hardener and wheat flour (30%) as the filler based on the dry weight of the adhesive characteristics of adhesives included solid material percentage, viscosity, specific weight and PH were measured. After producing the laboratory boards, the physical and mechanical properties of samples, such as thickness swelling after 2 and 24 hours of being soaked in water, shear strength, modulus of rupture, and modulus of elasticity were measured. In addition, the groups and bonds in the pure lignin and lignin-gloxal adhesives were identified by Fourier Transform Infrared (FTIR) spectroscopy. The results indicated that the independent effect of adhesive type on the thickness swelling of plywood after 2 and 24 hours was significant. Although the results suggest that modifying the lignin would improve the plywood in all cases, the control boards had better featurers than those made with the Lignin-Glyoxal adhesive.
Pulp and paper
vida haji Aghaei; Seeyed Ahmad Mirshokraie; Tayyebe partovi
Abstract
In this study, the structure of Soda (soluble fraction in ethanol) and Dioxane lignins of bagasse were studied by using derivatization followed by reductive cleavage (DFRC) method and some techniques including gel permeation chromatography, gas chromatography-mass spectrometry and 13C-nuclear magnetic ...
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In this study, the structure of Soda (soluble fraction in ethanol) and Dioxane lignins of bagasse were studied by using derivatization followed by reductive cleavage (DFRC) method and some techniques including gel permeation chromatography, gas chromatography-mass spectrometry and 13C-nuclear magnetic resonance spectroscopy and the results were compared. These comparative results show that the main monomeric compounds are obtained from the cleavage of β-O-4 bonds of lignins. The components obtained from Dioxane lignin and Soda lignin are guaiacyl, syringyl and p-hydroxyphenyl structures with different proportions. However, some differences have been observed in both lignins, including a variety of structural units in Dioxane lignin is greater than Soda lignin. In other words, soda lignin degradation and the structural components has become closer together and are more uniform structures. The average molecular weight of Dioxane lignin, is greater than Soda lignin, which is due to Soda lignin wide chemical degradation during industrial pulping processes and therefore it has less dense structure. These observations indicate that a mild method for lignin separation from a lignocellulosic material caused less damage and changes in lignin structure. Therefore, in structural studies, Dioxane lignin can actually be used as an appropriate representative of the lignin.
Physics and Mechanical Wood
Hamideh Abdolzadeh; Ghanbar Ebrahimi; Mohammad Layeghi; Mehdi Ghasemieh; Seiad Ahmad Mirshokraei
Abstract
In this study, characteristics of wood-polymer fracture under mode I were investigated by double cantilever beam. In this regard, the properties of furfurylated specimens with three different levels of furfurylation (20%, 30% and 65%) were evaluated in both RL and TL systems. Results indicated that load-displacement ...
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In this study, characteristics of wood-polymer fracture under mode I were investigated by double cantilever beam. In this regard, the properties of furfurylated specimens with three different levels of furfurylation (20%, 30% and 65%) were evaluated in both RL and TL systems. Results indicated that load-displacement curves from mode I fracture specimens were changed by furfurylation so that it was much clear on curves of TL system. These changes not only included curve slope in elastic and proportional limit zones, but also fracture zone and initiation of crack growth were included . Furthermore furfurylation and raising its content on both systems and especially on TL one, caused to change in stress intensity factor, KIC , and critical energy release rate , GIC. In both systems GIC were highly increased by increasing of furfurylation contents. This criterion demonstrated that the wood- polymer showed much toughness under mode I fracture. Moreover, variation of KIC values due to furfurylation at both systems was different with that of GIC. At the RL system, ascending trend was observed at KIC and GIC values by increasing furfurylation levels. But at TL system, KIC was decreased by furfurylation and this criterion enhanced by increasing of furan polymer in the cell wall. Generally, results of this research show that fracture toughness of wood is highly affected by furfurylation process
Jafar Azimvand; Seeyed Ahmad Mirshokraie; Ali Abdolkhani
Abstract
In this study, the chemical changes of functional groups (C=O) and double bond (C=C), induced in the structures of poplar kraft lignin and bagasse soda lignin were investigated. The reducing effect of sodium borohydride and sodium hydrosulfite, followed by the UV irradiation on these two compounds were ...
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In this study, the chemical changes of functional groups (C=O) and double bond (C=C), induced in the structures of poplar kraft lignin and bagasse soda lignin were investigated. The reducing effect of sodium borohydride and sodium hydrosulfite, followed by the UV irradiation on these two compounds were determined using FT-IR spectroscopy. Results showed that, reduction of the lignin by reducing chemical imparted stability in lignin structure against UV light. The FT-IR spectroscopy showed that, the major light stabilizing phenomenon that is responsible for this stability is the conversion of carbonyl groups (C=O) alcohol group (C-OH) and double bonds (C=C) to single bonds (C-C). Between the two reducing compound, sodium borohydride showed better performance than sodium hydrosulfite.
Pulp and paper
Pyvand Darabi; Hamideh Abdolzadeh; Ali naghi Karimi; Seeyed Ahmad Mirshokraie; Kazem Doosthoseini
Abstract
In this study capability of acetylated poplar flour in manufacture of high density poly ethylene composite which expose to accelerated weathering, was investigated. The acetylation degrees at medium and zero (control) levels, use of anti- oxidant and duration of weathering were considered as variables ...
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In this study capability of acetylated poplar flour in manufacture of high density poly ethylene composite which expose to accelerated weathering, was investigated. The acetylation degrees at medium and zero (control) levels, use of anti- oxidant and duration of weathering were considered as variables and their effects on discoloration and photodegradation of WPC were investigated. To determine treatments influence on changes and color fade resulting from weathering, samples were tested after o, 250, 2000 hours of weathering. The results indicated that application of acetylated wood flour in WPC can reduce about 25% of weathering discoloration in short time and about 17% in long time. Also it shows that as exposed time of weathering increase Anti oxidant loss its effect. Although in short time it can reduce 12% of weathering color changes. FTIR results show that after 2000 h of weathering all peaks samples had same decrease which mean none of the treatments were useful. But Anti oxidant can reduce depth of weathering.
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.
Chemistry of wood
Sayed ahmad Mirshokraei; Ali Abdolkhani; Alinaghi Karimi
Abstract
In this paper, a novel enzymatic method was evaluated for isolation and purification of wood lignin. The chemical structure of enzymatic lignin (Cellulytic lignin) was compared with conventional Bjorkman method (Milled wood lignin). The chemical structure elucidation was performed ...
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In this paper, a novel enzymatic method was evaluated for isolation and purification of wood lignin. The chemical structure of enzymatic lignin (Cellulytic lignin) was compared with conventional Bjorkman method (Milled wood lignin). The chemical structure elucidation was performed with FTIR, quantative 13CNMR, basic elemental analysis and Gel Permeation Chromatography (GPC). The results showed that enzymatic lignin preparation has a better chemical structure than MWL. Comparing to conventional isolation methods, application of an enzyme sequence with reduced milling time could lead to a mild extraction with less structural degradation of lignin. Resulting lignin could be more representative for wood lignin than milled wood lignin.
Pulp and paper
Amir mohsen Nazeri; Mohammad Talaeipoor; Seeyed Ahmad Mirshokraie
Abstract
The present study deals with effects of CMP fines on optical and physical properties of newsprint papers, for which, different batches for CMP fines (0%, 10%. 20%. 30%) of totally 80% pulp is taken, Where the remaining 20% of imported long fiber pulp was taken as fixed amount .
The study ...
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The present study deals with effects of CMP fines on optical and physical properties of newsprint papers, for which, different batches for CMP fines (0%, 10%. 20%. 30%) of totally 80% pulp is taken, Where the remaining 20% of imported long fiber pulp was taken as fixed amount .
The study focused on surving the effects of CMP fines on optical and physical properties of newsprint paper ,after mixing the pulps and making the handsheets .
Generally, the results show the increase in CMP fine amount lead to increase ,Air Resistance and Opacity and decrease Caliper and Roughness, Also that changes in CMP fines has no effect on Brightness .
Composite wood products
asghar tarmian; Kazem Doosthosseini; Seeyed Ahmad Mirshokraie; Mohammadmehdi Faezi poor
Abstract
Beneficial utilization of large quantity of paper sludge from Mazandaran Wood & Paper Industry in particleboard manufacturing has been studied. Single-layer and three-layer particleboard (paper sludge as a surface layer) were produced. Urea-formaldehyde resin at two levels of 10 and 12 percent and ...
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Beneficial utilization of large quantity of paper sludge from Mazandaran Wood & Paper Industry in particleboard manufacturing has been studied. Single-layer and three-layer particleboard (paper sludge as a surface layer) were produced. Urea-formaldehyde resin at two levels of 10 and 12 percent and paper sludge content at 4 levels, 0, 15, 30 and 45 percent were studied. Other factors such as press temperature (160oC), press time (6minutes), mat moisture (12%), board density (0.75g/cm3) and etc were constant factors. Mechanical and physical properties including bending strength, shear strength, thickness swelling and water absorption after 2 and 24 hours immersion were evaluated. The results indicated that application of paper sludge reduced mechanical properties and improved thickness swelling .The particleboard produced with 15%paper sludge had the least water absorption, but by using more paper sludge, water absorption increased. Single-layer particleboard had higher bending strength. However, there was no significant different in shear strength between single and three layer particleboard. Three-layer particleboard showed lower thickness swelling.
