Pulp and paper
bardia sodeifi; Seyed Hassan Sharifi
Abstract
Background and objectives: The use of polymers with petroleum derivatives in the packaging industry has caused environmental problems due to their non-biodegradability. Development of active and biodegradable packaging is possible by coating biopolymers on packaging materials. In this research, we tried ...
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Background and objectives: The use of polymers with petroleum derivatives in the packaging industry has caused environmental problems due to their non-biodegradability. Development of active and biodegradable packaging is possible by coating biopolymers on packaging materials. In this research, we tried to use biodegradable materials that are easily decomposed after use in the environment. In this regard, the effect of different treatments with Carboxymethyl chitosan (CMCh), purified Guar gum (PGG) and Nanocrystalline cellulose (NCC) on resistance and barrier properties.Methodology: Carboxymethyl chitosan powder and purified Guar gum were dissolved separately in distilled water along with glycerol (40% by weight of biopolymers) as softener. Then the bio composite solutions were heated on a magnetic stirrer for 120 and 90 minutes until the biopolymers were completely dissolved. At the end, they were kept in a static state for 30 minutes to cool down and remove the air bubbles completely. Also, Nanocrystal cellulose suspension (3, 6 and 9% compared to biopolymers) prepared by dissolving in distilled water by ultrasonic device for 3 minutes was added to bio composite solution with mixed ratios (30:70, 50:50 and 70:30) was added and the final suspension was heated on a magnetic stirrer for 120 minutes and it was completely dissolved. Then, in order to cool down and remove the air bubbles completely, it was put in a static state for 30 minutes. At the end, we centrifuged it and let it stand still for 2 minutes to completely remove the air bubbles. Finally, 25 grams of gel was poured into a polystyrene petri dish with a diameter of 10 cm and the petri dishes were placed in an oven at 50 °C for 24 hours. Also, the morphological tests of Carboxymethyl chitosan and bio Nano composite films and the resistance and barrier characteristics of the treatments were studied.Results: The results of measuring the resistance characteristics of biopolymer films showed that with the increase of Nanocrystal cellulose up to the level of 6%, the tensile strength of the treatments increased significantly, and the highest amount was related to the films CMCh/PGG/NCC (50/50/6%). is Also, with the increase of cellulose Nanocrystals up to the level of 9% due to the accumulation of Nanocrystal particles in one area, the tensile strength of bio nano composites decreased. Also, due to the origin of its crystallinity, cellulose Nanocrystals led to the brittleness and reduced flexibility of the treatments to reduce the Elongation at break of bio nano composite films. The solubility of bio composite films has decreased by adding NCC to the biopolymer matrix due to the establishment of hydrogen interactions between the components of this matrix with nanoparticles at different levels, and the lowest water Solubility is related to the films CMCh/PGG/NCC (50/50/6%). The water vapor permeability of the treatments decreased by adding NCC to the CMCh/PGG matrix due to reasons such as the crystalline structure and the hydrophobic nature of cellulose fibers, the reduction of pores and the reduction of the diffusion coefficient of vapor molecules, and the best impermeability was obtained by films CMCh/PGG/NCC (50/50/6%) because of uniform dispersion of nanoparticles.Conclusion: According to the results, by adding cellulose Nanocrystals to the composite suspension; Tensile strength, resistance to water solubility and impermeability to water vapor of the films increased and only their Elongation at break decreased and the best resistance and barrier properties of bio nano composites produced in the presence of 6% Nanocrystalline cellulose were obtained.
Nano composite
Bardia Sodeifi; Seyed Hassan Sharifi; Noredin Nazarnezhad
Abstract
Development of active and biodegradable packaging is possible by coating biopolymers on packaging materials. In this research, in order to improve the mechanical and barrier properties of polycaprolactone polymer films, cellulose nanocrystals obtained from alpha-cellulose of cotton linter were added ...
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Development of active and biodegradable packaging is possible by coating biopolymers on packaging materials. In this research, in order to improve the mechanical and barrier properties of polycaprolactone polymer films, cellulose nanocrystals obtained from alpha-cellulose of cotton linter were added to the poly caprolactone composite solution with amounts of (3%, 6%, and 9%), and their structural, mechanical, and barrier properties were investigated. According to the results of the field emission scanning electron microscopy (FESEM) test, the obtained nanoparticles are rod-shaped and have a length in the range of 100 to 150 nm and a diameter of 10 to 50 nm. X-ray diffraction (XRD) confirmed the formation of cellulose nanocrystals. According to the results, by adding cellulose nanocrystals to the composite solution, tensile strength, resistance to water solubility, and impermeability to the water vapor of the films increased, and only the elongation at break reduced. The best mechanical and barrier properties of the nanocomposites were obtained in the presence of 6% cellulose nanocrystals.
Pulp and paper
Bardia Sodeifi; noureddin Nazarnezhad; Seyed Hassan Sharifi
Abstract
DOR:98.1000/1735-0913.1398.34.45.66.1.1576.1610 In this research, the effect of coating with Polycaprolactone (PCL), nanocrystalline Cellulose (NCC) and zinc oxide Nanoparticle (ZnO NP) and their blend were investigated on the mechanical and optical properties. First, coating materials with specific ...
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DOR:98.1000/1735-0913.1398.34.45.66.1.1576.1610 In this research, the effect of coating with Polycaprolactone (PCL), nanocrystalline Cellulose (NCC) and zinc oxide Nanoparticle (ZnO NP) and their blend were investigated on the mechanical and optical properties. First, coating materials with specific condition (PCL 10%, NCC 4 and 6%, ZnO 3%) were coated on the papers. The coating materials weight on the papers was (2.2- 2.7 g/m2). The results showed that the mechanical properties (Tensile strength index, Burst strength index and Tear strength index) of the coated papers were enhanced with addition of NCC. The ternary blend of these coating materials had the best mechanical properties than the neat paper. With addition of NCC the brightness were enhanced and the opacity were reduced. Also, the color properties were improved with addition of NCC and ZnO and the effect of ZnO was more remarkable than NCC but, in ternary blend of materials, the color properties were improved with increasing the amount of NCC.
