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 ...
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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.
khadijeh armand; ali ghasemiyan
Abstract
In this research, the effect of sodium peroxide and sodium hypochlorite on the chemical-mechanical pulp bleaching (CMP) has been investigated. For this purpose, unbleached CMP pulp was produced from Mazandaran wood and paper mill, and bleaching with hydrogen peroxide and sodium hypochlorite was carried ...
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In this research, the effect of sodium peroxide and sodium hypochlorite on the chemical-mechanical pulp bleaching (CMP) has been investigated. For this purpose, unbleached CMP pulp was produced from Mazandaran wood and paper mill, and bleaching with hydrogen peroxide and sodium hypochlorite was carried out in two levels of 3 and 4%, during both 60 and 90 minutes in 70°C at 8% consistency. In each treatment, 30 grams of pulp with hydrogen peroxide, sodium silicate, DTPA, sodium hydroxide and sodium hypochlorite for bleaching were prepared. In the following 60 gr/m2 hand sheets were prepared and the optical properties of hand sheets were measured and analyzed based on TAPPI.The results obtained from the review of optical properties of handsheets show that by increasing the bleaching time and the level of chemicals the optical properties was improved. So that the highest brightness and minimum yellowness were observed in the 4% and 90 minutes in bleaching whit hydrogen peroxide. the lowest opacity in the control sample. Resistance properties such as tensile, burst and tear strength of bleached paper were also increased.
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 ...
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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.
