Pulp and paper
Kajal Moradian Gilan; Sahab Hedjazi; Ali Abdulkhani; Herbert Sixta
Abstract
In this research, the effect of hot water and alkaline pre-extractions on properties of bagasse monoethanolamine-AQ pulps was investigated and the results were compared with that of soda pulping. The pre-extraction with alkaline charge of 10%, time of 30 min resulted in total yield and holocellulose ...
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In this research, the effect of hot water and alkaline pre-extractions on properties of bagasse monoethanolamine-AQ pulps was investigated and the results were compared with that of soda pulping. The pre-extraction with alkaline charge of 10%, time of 30 min resulted in total yield and holocellulose of 94.7% and 71.6%, respectively. The hot water pre-extraction with L/W of 10/1 and time of 45min lead to total yield and hollocellulose of 94% and 69.4%, respectively. These trails were selected as the optimum conditions. Monoethanolamine was used as pure and also in different proportions with water for cooking unextracted and pre-extracted bagasse. Variables in monoethanoleamine pulpng were ratio of monoethanolamine to water at three levels (100/0, 75/25, and 50/50%) and the ratio of the liquor to bagasse of 6 to 1, cooking time of 60 min, the temperature of 165°C and AQ charge of 0.1% considered as constant. According to the results, the MEA-AQ pulps produced with MEA/H2O ratio of 75/25 (from unextracted bagasse) have the highest total yield (61.9 %) and the acceptable kappa number (19.5). Pre-extraction resulted in improving of the yield in both MEA-AQ and soda pulping processes. After pre-extraction, the tensile index and breaking length of pulps dropped. In contrast, the tear index of pulps produced from pre-extracted bagasse in both pulping processes was increased. The brightness of soda pulps from un- and pre-extracted bagasse was more than that of MEA-AQ pulps. After pre-extraction, the opacity of pulps remains almost unchanged.
Management and Economics wood
Seyed Mahmoud Miri Tari; asghar tarmian; Mohammad Azadfallah; Abdolkhani Ali; Davood Efhamisisi
Abstract
DOR:98.1000/1735-0913.1398.34.45.66.1.1575.1575 Mold growth resistance of Polyurethane and Diotrol coatings containing natural (Thyme essential oil) and synthetic (IPBC) fungicides in both free and microencapsulated forms was studied. Polymethyl methacrylate (PMMA) microcapsules were prepared using solvent ...
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DOR:98.1000/1735-0913.1398.34.45.66.1.1575.1575 Mold growth resistance of Polyurethane and Diotrol coatings containing natural (Thyme essential oil) and synthetic (IPBC) fungicides in both free and microencapsulated forms was studied. Polymethyl methacrylate (PMMA) microcapsules were prepared using solvent evaporation method by means of oil emulsion formation in water. Mold growth resistance against Aspergillus niger was determined by Filter Paper Disc method before and after aging process according to ASTM D 5590 Standard. Adhesion strength and surface roughness of coated samples were also measured. Results revealed that biocide-free coatings cannot provide adequate protection against mold growth, and addition of biocides, especially IPBC, significantly improved the mold growth resistance. Even after the aging process, microencapsulated biocides were able to provide better protection against mold growth due to controlled-release mechanism and shielding-effect of polymeric shell. Although the surface roughness of polyurethane coating was increased by using of biocides in both forms, especially microencapsulated ones, its adhesion strength reduced.
Chemical conversion
Atefe Rahimi; Ali Abdolkhani; Yahya Hamzeh; Sahab Hedjazi
Abstract
DOR:98.1000/1735-0913.1398.34.124.66.1.9.1580 Rice straw rice is one of the most important lignocellulose wastes in Iran and the world. In this research, rice straw as renewable lignocellulosic materials were used to produce nano-structural lignocellulosic aerogel. For this purpose, rice straw powder ...
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DOR:98.1000/1735-0913.1398.34.124.66.1.9.1580 Rice straw rice is one of the most important lignocellulose wastes in Iran and the world. In this research, rice straw as renewable lignocellulosic materials were used to produce nano-structural lignocellulosic aerogel. For this purpose, rice straw powder was first pre-treated in sodium hydroxide aqueous alkali solution and resulting gel form mixture was transformed into physically bonded lignocellulosic porous and ultra-lightweight aerogel through consecutive processes including freezing-thawing, solvent exchange and freeze-drying. The product properties including apparent density and total porosity were determined, and other physical and chemical properties were evaluated by SEM, FTIR, XRD, nitrogen absorption (BET) and DSC methods. The results showed that a significant amount of the rice straw compounds dissolved in aqueous alkali solution and removed during the subsequent stages of aerogel production. The resulting aerogel showed a nano dimensional structure composed of particles and interconnected nanofibers, which had a great chemical and physical difference from the original rice straw.
Pulp and paper
zahra takzare; kermanian hossein; omid ramezani; Esmaeil Rasooly Garmaroody; Ali Abdolkhani
Abstract
In this study, the liquorice root (Glycyrrhiza glabra) has been extracted in the Liquorice factory of Kerman, supplied as raw material. The above mentioned waste, after pre-hydrolyzed with sulfuric acid 2% at 130 °C in 60 minutes, is cooked at temperatures of 170 ̊C, the chemicals charge of 20%, ...
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In this study, the liquorice root (Glycyrrhiza glabra) has been extracted in the Liquorice factory of Kerman, supplied as raw material. The above mentioned waste, after pre-hydrolyzed with sulfuric acid 2% at 130 °C in 60 minutes, is cooked at temperatures of 170 ̊C, the chemicals charge of 20%, and in four times 15, 30, 60 and 90 minutes and rate of liquor to waste 7:1 in Soda process. Obtained Soda pulps were evaluated in yield, lignin percentage, water retention value (WRV), viscosity and crystallinity. Results showed that by prolonging of cooking time, pulp yield and lignin percentage were decreased and WRV increased. Also, pulp viscosity in 30, 45 min was increased by increasing in cooking time that according to other results, it seems that it is false viscosity. In addition, accordance with characterizing of samples by XRD, by progressive cooking time from 15 to 45 min, sample crystallinity decreased and in 60 min its value is increased. According to the pulps viscosity and downward trend of lignin removal with progressive cooking time, this addition can be due to crystallization of hemicellulose like xylan on the crystalline zone of cellulose chain. Therefore, according to the results and based on Bio-refinery concept, cooking time 30 min suggested as the best option for production of high value-added products in saccharification process.
Management and Economics wood
Hadi gholamian; Asghar Tarmian; Ali Abdulkhani
Abstract
In present study, the adhesion strength of polyurethane and alkyd coatings on the poplar wood (Populus nigra) was improved by nano-silane coating using sol-gel method for outdoor application. For this purpose, the boards with dimensions of 15 × 10 × 2 mm were prepared according to EN 927-5. ...
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In present study, the adhesion strength of polyurethane and alkyd coatings on the poplar wood (Populus nigra) was improved by nano-silane coating using sol-gel method for outdoor application. For this purpose, the boards with dimensions of 15 × 10 × 2 mm were prepared according to EN 927-5. The surfaces of wood specimens were modified with Tetraethoxysilane (T) sol-gel material and then, solvent-borne alkyd (AS) and solvent-borne polyurethane (PS) coatings were applied. The coated samples were placed outdoor on a platform with a slope close to Karaj latitude (36̊) for 8 months according to ISO 877 standard. In order to characterize the quality of the coatings, colorimetric, tensile adhesion (Pull off), scratch adhesion (Cross cut) and ATR-FTIR tests were performed before and after weathering. The ATR-FTIR analysis demonstrated that the wood surface was covered with silicon oxides (SiO2) attached to hydrocarbon chains. As a result of surface wood modification by sol-gel, the color and adhesion strength of polyurethane and alkyd coatings were less affected by weathering. The highest tensile and scratch adhesions were found for the combined sol-gel and polyurethane coatings.
Pulp and paper
Jaber Hossein zade; Ali Abdolkhani; Mohammad Emami nasab; Hamid Khodabandeh lo; Mohammad Ahmadi
Abstract
In this research Tension Wood (TW) and Normal Wood (NW) of Poplar were analyzed for pulp production using Kraft pulping process. After preparing samples, Biometric characteristics of the NW and TW fibers were measured and samples were converted to pulp. Pulp hand sheets mechanical and physical properties ...
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In this research Tension Wood (TW) and Normal Wood (NW) of Poplar were analyzed for pulp production using Kraft pulping process. After preparing samples, Biometric characteristics of the NW and TW fibers were measured and samples were converted to pulp. Pulp hand sheets mechanical and physical properties were measured and results were showed that NW fibers compared to TW fibers had a higher Rankle coefficient and aspect ratio. However the flexibility of NW fibers was better than TW fibers. Based on Results, although TW pulp yield was 13 percent greater than NW pulp yield but kappa number in TW was 45 percent lower than NW. Mechanical and physical properties of hand sheets indicated that the tensile and burst strengths of tension wood were comparatively lower than that of normal wood. Also the papers produced by equally mixture of TW fibers and NW fibers were showed higher tensile and burst strengths. Optical and color analyses of samples were showed an improvement in brightness and whiteness for TW hand sheets compared to NW papers. General speaking results were showed that presence of TW fibers inside pulp had not a significant effect on quality of produced pulp and papers.
Ahmad Mirshkraee; Jalil Lari; Fatemeh Mstaghni; Ali Abdolkhani
Abstract
In this study, optical behavior of methylated and unmethylated Bjorkman lignin from poplar wood and two lignin model compound (phenolic and non phenolic) with β-O-4 linkages was investigated. First, these lignins were precipitated on a cellulosic matrix (Whatman Paper) using different times ...
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In this study, optical behavior of methylated and unmethylated Bjorkman lignin from poplar wood and two lignin model compound (phenolic and non phenolic) with β-O-4 linkages was investigated. First, these lignins were precipitated on a cellulosic matrix (Whatman Paper) using different times (0, 5, 10, 15, 20 h) and then matrixcovered surface was analyzed using Attenuated Total Reflectance FTIR technique. The results showed that irradiation altered the chemical structure of all samples. Lignin was the most sensitive component to photodegradation and the intensities of its characteristic bands decreased significantly during the process of irradiation. This was accompanied by formation of new carbonyl groups appearing at 1735 cm_1. Compared with the unmethylated forms, the rate of lignin degradation and carbonyl formation was relatively lower in methylated forms. In other words, methylation of phenolic hydroxyl group reduced the chemical changes induced by irradiation.
Pulp and paper
farzaneh shiralizadeh; mohammad azadfallah; ali Abdolkhani; mohammad Layeghi; saeed mahdavi
Abstract
This study was conducted with the aim of producing laboratory samples of transparent paper using overbeating method. Hence, bagasse bleached soda pulp was subjected to post-bleaching sequence of DED to remove residual chromophores. Then this pulp was refined in a PFI mill to reach different ...
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This study was conducted with the aim of producing laboratory samples of transparent paper using overbeating method. Hence, bagasse bleached soda pulp was subjected to post-bleaching sequence of DED to remove residual chromophores. Then this pulp was refined in a PFI mill to reach different levels of 55, 130, 200, and 260 mL,CSF (Canadian standard freeness) freeness. Then handsheets were made according to TAPPI standard T 205 om– 8. Results indicated that refining has significant effect on optical properties especially transparency so that the maximum value was observed using pulp with the minimum freeness, i.e. 55 ml. The variations of transparency due to refining were also further explained by measuring scattering coefficient, opacity and brightness of the specimens. In addition, mercury porosimetry and analyzing the pictures of scanning electron microscopy (SEM) demonstrated the extensive variations of pore structure in paper during refining which impose great influence on developing transparency.
Ebrahim HojatiMarvast; Ali Abdolkhani; Alinaghi Karimi
Abstract
Dissolution and Cellulose-Nylon composites preparation in liquid phase was studied. BMIMCl ionic liquid was synthesized in the laboratory and was used to perform the dissolution purpose. After the dissolution of the polymers, Cellulose and Cellulose-Nylon composite films were prepared and processed. ...
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Dissolution and Cellulose-Nylon composites preparation in liquid phase was studied. BMIMCl ionic liquid was synthesized in the laboratory and was used to perform the dissolution purpose. After the dissolution of the polymers, Cellulose and Cellulose-Nylon composite films were prepared and processed. Then the transparency, water absorption and thickness swelling, water vapor permeability and tensile strength of the composite were determined. Further characterization was performed using SEM and FTIR techniques. Results showed that both polymers were compatibly dissolved in Ionic liquid and homogenously blended which indicates chemical bonding was established between the polymers. Transparency, water absorption and thickness swelling decreased and water vapor permeability of the composites increased compared to pure cellulosic film. Also, mechanical strength, Young's modulus and strain at break point of the composite were decreased compared to reference cellulosic film.
kezhal Moradyan Gilan; Mohammad Azad fallah; Amir abbas Shayghani akmal; Ali Abdolkhani
Abstract
This research was carried out with the aim of determining dielectric properties of bagasse unbleached soda pulp, long fiber kraft pulp and a mixture of both (20% kraft + 80% bagasse soda).The hand-sheets with 60 g/m2 basis weight were made after adjusting the freeness of pulps at levels of 200 ± ...
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This research was carried out with the aim of determining dielectric properties of bagasse unbleached soda pulp, long fiber kraft pulp and a mixture of both (20% kraft + 80% bagasse soda).The hand-sheets with 60 g/m2 basis weight were made after adjusting the freeness of pulps at levels of 200 ± 25 ml and 400± 25 ml and dried under mild condition around zero moisture content. Then the impregnation processes were carried out with mineral oil under vacuum at certain temperature. Finally the dielectric properties of impregnated papers including capacitance, insulation resistance, dielectric constant, and loss tangent were measured. The results showed that the refining give rise to enhance the dielectric properties in particular capacitance value. The dielectric properties of oil impregnated paper also increased. According to the preliminary results, unbleached soda bagasse pulp and its mixture with kraft pulp (20% Kraft -80% bagasse soda) found to be the suitable alternative with respect of dielectric applications for replacing kraft pulp, providing successful performance of the aging test.
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.
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
Aghdas Sadeghi; Ali Abdolkhani; Yahya Hamzeh; Ahmad Mirshokraei; Alinaghi Karimi
Abstract
In this study the pulping of bagasse using TMAH and EDA as organic bases was investigated and compared to conventional Soda and Soda-AQ bagasse pulping. Resulting pulps properties including Kappa number, reject, screen yield of pulp and optical and mechanical properties of handsheets prepared from them ...
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In this study the pulping of bagasse using TMAH and EDA as organic bases was investigated and compared to conventional Soda and Soda-AQ bagasse pulping. Resulting pulps properties including Kappa number, reject, screen yield of pulp and optical and mechanical properties of handsheets prepared from them were determined and compared. Kappa number of TMAH pulp was considerably lower than others. Also, optical properties of TMAH and TMAH-NaOH pulps were considerably higher than Soda and Soda-AQ reference pulps. As well as, addition of EDA to pulping liquor resulted suitable pulp with better properties compared to Soda pulp. Based on the obtained results, it was concluded that the delignificatiom mechanism of TMAH differ to hydroxide ion from NaOH and probably it improves the delignification rate through increasing of lignin degradation and its solubility.
Pulp and paper
Yahya Hamzeh; Mohammad hassan Ekhtera; Ali Abdolkhani; Sohila Ezadyar; Kambiz Pourtahmasi
Abstract
In this study the effects of several parameters on the sizing efficiency of test liner using poly aluminum chloride and rosin under neutral condition in reverse and premixing sizing processes were investigated. The results indicated that the individual effects of poly aluminum chloride amount, rosin ...
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In this study the effects of several parameters on the sizing efficiency of test liner using poly aluminum chloride and rosin under neutral condition in reverse and premixing sizing processes were investigated. The results indicated that the individual effects of poly aluminum chloride amount, rosin amount, interval time as well as interaction effect of poly aluminum chloride -rosin amounts in both sizing processes affect significantly sizing performance. The most important variable was the poly aluminum chloride amount. The effect of poly aluminum chloride amount on the sizing efficiency depended on the properties of fiber surfaces. This study showed that the interval time on the sizing efficiency is significant. To obtain an identical degree of sizing, it is possible decrease the amount of poly aluminum chloride and rosin amounts by increasing the interval time. In addition, the results confirmed two different mechanisms involved in the premixing sizing process.
