Noraldin Nazarnezhad; mahin avrand; Hosin Resalati
Abstract
One of the problems of papers and cardboards in the packaging industry is the poor resistance to water, gas, and oil penetration. Nowadays, much research have been done on the use of biodegradable films and coatings based on polysaccharides to solve this problem. Chitosan is one of these polysaccharides ...
Read More
One of the problems of papers and cardboards in the packaging industry is the poor resistance to water, gas, and oil penetration. Nowadays, much research have been done on the use of biodegradable films and coatings based on polysaccharides to solve this problem. Chitosan is one of these polysaccharides that can be used as a biodegradable coating in packaging papers. In this study, the effect of chitosan on the strength and barrier properties of coated liner paper was investigated. Chitosan was used in three levels 10, 15, and 20 g/L acetic acids (1%) and with two softener ratios (glycerol) of 0.5 and 1 (based on dry weight of chitosan) for papers coating. Strength properties including tensile, burst and tear index and barrier properties including water absorption, air resistance, and oil absorption in the coated samples were investigated. The Statistical analysis of results showed that the barrier properties increased significantly. Also, the effect of increasing the concentration of softener in the coating solution on the properties of air resistance and oil absorption was positive but negative for water absorption. The basis weight, burst and tear index of the coated samples increased with increasing coating weight, on the other hand the tensile strength decreased. Moreover, increasing the concentration of softener in the coating solution showed a negative effect on the properties of the samples. The results of the scanning electron microscope images showed that formation of chitosan film and the increase in the uniformity of the liner paper surfaces, especially in higher consumption amounts.
Aisona Talaei; Vahid Heydari
Abstract
In the present study, the functional properties of medium-density fiber board made with formaldehyde urea resin as a control with MDF made with chitosan and carboxylic acids were investigated and compared. Various compounds including chitosan acetate solution, chitosan acetate –butane tetra carboxylic ...
Read More
In the present study, the functional properties of medium-density fiber board made with formaldehyde urea resin as a control with MDF made with chitosan and carboxylic acids were investigated and compared. Various compounds including chitosan acetate solution, chitosan acetate –butane tetra carboxylic acid solution, chitosan acetate -citric acid solution and citric acid solution were investigated. The chemical structure of specimens was investigated by infrared spectroscopy (FTIR). The results of spectroscopy clearly showed the difference in the use of different compounds. The formation of cross-links between cellulose chains and carboxylic acids was confirmed, as well as the formation of hydrogen bonds between chitosan and lignin. Specimens made with the combination of acetate chitosan-BTCA showed better dimensional stability. Also, the internal bonding of MDF specimens made with chitosan acetate solution was higher than controls. Boards made of Chitosan acetate -BTCA compound can be considered as a successful substitute for urea-formaldehyde adhesive due to its better dimensional stability and good internal bonding.
khadijeh armand; ali ghasemiyan
Abstract
This study was carried out to determine the effect coating polylactic acid-chitosan complex on the packaging paper by two methods of mixing and grafting. For this purpose was made handsheet (80 g/m2) of long fibers that prepared from Mazandaran Wood and Paper Factory. Therefore, poly lactic acid, chitosan ...
Read More
This study was carried out to determine the effect coating polylactic acid-chitosan complex on the packaging paper by two methods of mixing and grafting. For this purpose was made handsheet (80 g/m2) of long fibers that prepared from Mazandaran Wood and Paper Factory. Therefore, poly lactic acid, chitosan and nanocytosis with concentration of 1 wt% , were prepared by dissolving in chloroform and 1% acetic acid, respectively. In both method done coating with three layers. Then, coated samples dried in oven. In the mixing method, polylactic acid and chitosan were mixed then coated on base paper. In the grafting method, by chemical modification of chitosan and polylactic acid, 0.01 g of EDC( N-(3-dimethy laminopropyl)-N/-ethylcarbodiimide hydrochloride) , 0.1 g of Span 80 and 0.047 g of HOBT( 1- Hydoxybenzotriazole) homogeneous solution were prepared and placed on a paper surface. Finally, investigated barrier and mechanical properties including contact angle, water absorption, air permeability and burst strength respectively. The results showed that papers which were coated with grafting method, with three layers of coating (P3nCs3) had the most strength air permeability compared to the mixing method, control sample showed minimum strength to air permeability. Water absorption decreased in coated samples by mixing method compared to grafting method that showed grafting method further reduced water absorption. Contact angle increased in coated samples by the grafting method compared to the mixing method.
shaghayegh rezanezhad; Hossein Resalati; Seyed Majid Zabihzadeh
Abstract
The most important challenges of using minerals and fillers in the papermaking process are low retention and sharp reduced paper strength properties. In this research, magnetic papers were synthesized using commercial kraft fibers and iron salts. Nano-iron oxide has the same performance as fillers, as ...
Read More
The most important challenges of using minerals and fillers in the papermaking process are low retention and sharp reduced paper strength properties. In this research, magnetic papers were synthesized using commercial kraft fibers and iron salts. Nano-iron oxide has the same performance as fillers, as a result, to prevent reducing strengths properties and retention of material in the final paper, chitosan uses as a strength agent and retention aid at 0, 10 and 15% levels. Characteristics of magnetic papers were investigated by atomic force microscope, scanning electron microscope, X-ray diffraction and vibration sample magnetometer. Tensile index and tear index were also determined in magnetic paper samples. The results of the microscopic examination showed that the magnetite nanoparticles were in the size range of 1 to 84 nm and the magnetic materials completely covered the fibers surface. Also, increasing chitosan content, increased the degree of loading and magnetic saturation of the samples. The magnetic paper samples had super para magnetic behavior. The results showed that adding chitosan at 10% increased tear and tensile strength but 15% chitosan decreased the strengths properties of magnetic paper.
Ramin Vaysi; Yousef Yousefi-golordi
Abstract
This study was aimed to investigate the effect of cellulose nano-fibers and chitosan on optical and mechanical properties of chemi-mechanical pulp. For this purpose, some of the bleached CMP pulp of Mazandaran Wood and Paper Industries (MWPI) were randomly selected as a control sample. In addition, ...
Read More
This study was aimed to investigate the effect of cellulose nano-fibers and chitosan on optical and mechanical properties of chemi-mechanical pulp. For this purpose, some of the bleached CMP pulp of Mazandaran Wood and Paper Industries (MWPI) were randomly selected as a control sample. In addition, the cellulose nanofibers were used as a white gel at 3 levels of 0, 2, and 3%. The chitosan was then added to the CMP pulps suspensions at 5 levels of 0, 0.5, 1, 1.5, 2%, as well. Hand-sheets with a basis weight of 60 gr/m2 were prepared from the mentioned pulps. The optical and mechanical properties were then measured and compared using TAPPI standard test methods. The results showed that by adding chitosan, tear, tensile, burst and breaking length strengths, air resistance, yellowness, and greenness increased and brightness, Cobb 60 and a* factor decreased. On the other hand, with the addition of chitosan and nano-cellulose to CMP pulp, the tensile, burst, breaking length strengths, air resistance, Cobb 60, yellowness and a* factor increased and the tear, brightness, and opacity decreased. Moreover, the findings showed that by simultaneous adding 2% chitosan, 2% chitosan, and 3% cellulose nanofibers to the CMP pulp, most of the paper properties were improved. Therefore, it can also be introduced as the best treatment.
ali ghasemiyan; khadijeh armand; Elyas Afra; ahmad reza saraeian; mina salary
Abstract
The aim of this study was to investigate the effect of coating packing paper with polylactic acid-chitosan and polylactic acid-nano-chitosan complexes in two layer by layer and composite methods. For this purpose, was used of 80 grams long fiber handsheet paper Prepared from Mazandaran wood and paper ...
Read More
The aim of this study was to investigate the effect of coating packing paper with polylactic acid-chitosan and polylactic acid-nano-chitosan complexes in two layer by layer and composite methods. For this purpose, was used of 80 grams long fiber handsheet paper Prepared from Mazandaran wood and paper factory. For the preparation of coating material, 1% poly lactic acid in chloroform and 1% chitosan and nano chitosan in acetic acid were prepared. In both methods, up to three layers of coating were finally applied and the final layer in each treatment was poly lactic acid. The paper samples were then dried in an oven at a temperature of about 100 ° C. In the composite method, each material (chitosan and nano-chitosan) was mixed independently with poly lactic acid on a magnetic stirrer and then seating on a base paper. Finally, all papers were performed for barrier tests including contact angle measurement, water absorption (Cobb) and water vapor transmission rate (WVTR) and resistance tests including burst resistance and air penetration resistance. Based on the results, the barrier properties of the coated Samples in both methods (layer by layer and composite) were increased compared to the control sample. Also, the results of the study of composite and layer by layer methods showed that the LBL method causes more prohibition in the paper and increases the amount of prohibition with increasing the number of coating layers. It is worth noting, however, that between the second and third layers of coating, changes were less pronounced. These changes were observed in both the LBL and composite methods. Air Resistance was also increased in the coated samples.
Narges Ramezani; Amir Khosravani; Hamidreza Rudi
Abstract
Chitosan is one of the biopolymers which possesses unique properties and has been recently considered in various applications such as paper-making. This polymer is soluble in acidic conditions and has the potential to act as a polyelectrolyte under the colloidal condition in the pulp. However, according ...
Read More
Chitosan is one of the biopolymers which possesses unique properties and has been recently considered in various applications such as paper-making. This polymer is soluble in acidic conditions and has the potential to act as a polyelectrolyte under the colloidal condition in the pulp. However, according to the studies, the capability of this polyelectrolyte was better in alkaline condition, in improving the drainage, retention and even strength properties of paper. Therefore, in this study, the performance of chitosan was studied in different conditions and the results were investigated based on the interpretation of the adsorption process and chitosan configuration using silicon wafer model and ellipsometry technique. For this purpose, bleached kraft softwood fibers were refined to a Canadian standard freeness of 300 ml and after addition of chitosan and nano-silica at different pH levels, freeness and fines retention parameters were evaluated. The results of this study confirmed that chitosan polyelectrolyte showed a good performance in increasing drainage and retention at alkaline pH, compared to the other pH levels, lonely and with the addition of nano silica. However in freenes test at acidic pH, the addition of chitosan along with nanosilica reduced the drainage, and no significant effect was observed at neutral and acidic pHs in the case of fine retentions. In order to interpret these observations and to ratiocinate the behavior of chitosan polyelectrolyte, the data obtained from the ellipsometry technique was investigated to determine the configuration and the thickness of the adsorbed chitosan layer which showed a higher thickness of the polymeric adsorbed layer at alkaline pH, and thus, the possibility of the longer tail and loops configurations in the environment and more effective interractions beyond the electrical double layer.
Pulp and paper
masoumeh mollaei; Mohammad Azadfallah; Yahya Hamzeh; faramarz khodaian chegini
Abstract
The Effect of Chitosan - Poly (vinyl alcohol) Coatings on Strength and Barrier Properties of Packaging PaperAbstract In this research the mechanical and barrier properties of hand-sheets made of virgin and recycled fibers were studied after coating by chitosan and poly (vinyl alcohol) polymer blends. ...
Read More
The Effect of Chitosan - Poly (vinyl alcohol) Coatings on Strength and Barrier Properties of Packaging PaperAbstract In this research the mechanical and barrier properties of hand-sheets made of virgin and recycled fibers were studied after coating by chitosan and poly (vinyl alcohol) polymer blends. Therefore to evaluate coatings effects on barrier properties, water vapor transmission rate (WVTR), water absorbance, air resistance and grease proof of coated papers were determined. Moreover, mechanical strength including tensile strength and burst strength were measured. According to the results, the barrier properties and mechanical strength of coated papers improved dramatically than uncoated ones. The best results in WVTR and mechanical strength tests were obtained for coatings with the same ratio of polymers. On the other hand, coating with 75%chitosan - 25% poly (vinyl alcohol) composition exhibited excellent resistance against the grease penetration and water absorption.Keywords: Coating, chitosan, poly (vinyl alcohol), barrier properties, mechanical strength
