Document Type : Pulp and Paper
Authors
1 Graduated from Sari University of Agricultural Sciences and Natural Resources
2 Associated Professor, Wood and Cellulose Product Department, Sari Agricultural science and Natural Resources University, Sari, Iran
3 Retired Professor, Department of Pulp and Paper Industries, Gorgan University of Agricultural Sciences and Natural Resources. Faculty of Wood and Paper Engineering - Department of Pulp and Paper Industries
4 Wood and Paper Science Department, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resource University Sari, Iran
Abstract
Background and objectives: Carboxy methyl cellulose (CMC) is one the ether derivatives of cellulose and is widely used in various industries. This material is one of the most important and widely used cellulose derivatives, which has been considered in many researches as a substrate for the production of composite materials due to the presence of the carboxy methyl and hydroxyl groups. CMC can also be used as a substrate for the production of the magnetic cellulose compounds. Magnetic materials such as iron oxide are able to form effective bonds with hydroxyl groups in CMC and produce magnetic composites with biodegradable properties. The purpose of this research is to produce and analyze the magnetic properties of biocomposite made from CMC and then coat it on the surface of paper.
Methodology: In this research, CMC was used as a substrate for the production of magnetic biocomposite. The in-situ synthesis was used to produce biocomposite. In the process, iron salts (4 and 6 H2O) and CMC were mixed together in an aqueous solution and under nitrogen atmosphere, then by adding ammonium hydroxide to pH 11, iron oxide particles (magnetite) were formed on CMC. The materials were stirred in water bath for 1 hour at 40 °C, in order to complete the reactions and increase the production efficiency of magnetic particles. Handsheets with 120 ± 5 g/m2 weight was prepared by using commercial kraft fibers, and then coated with magnetic biocomposite. The synthesized magnetic materials and coated paper with magnetic biocomposite were analyzed by X-ray diffraction. The size of iron oxide was tested by an atomic force microscope. Also, the morphology and surface characteristics of magnetic particles, magnetic biocomposite and coated fibers and paper were investigated by scanning electron microscope. The magnetic properties of the samples were evaluated with a vibrating magnetometer. Furthermore, the strengths properties of the coated paper were examined with tensile, tear, water absorption and air resistance tests.
Results: The results of the magnetic test showed that in the first phase, the magnetic biocomposite was successfully prepared and the sample showed super paramagnetic properties. The highest magnetic saturation in the iron oxide sample was about 25 emu/g. Also, the CMC magnetic biocomposite had a magnetic saturation about 4 emu/g. The results of the microscopic evaluation of the iron oxide particles showed a uniform cubic structure. The formation of this structure is due to the accumulation of particles. In addition, mechanical engagement and connection of the magnetic biocomposite with the paper was observed. Also, the microscopic analyze of the iron oxide showed the most frequent of particles size were 45 nm. The results of the strength properties of the paper showed that the coating with magnetic material decreased the tensile and tear indices. The air resistance in the coated paper samples has increased compared to the control sample. Based on the results of Cobb test (water absorption), the lowest water absorption is related to the coated paper with CMC magnetic biocomposite. The X-ray diffraction pattern of the iron oxide sample showed five important peaks at 2 theta angles of 35, 41, 50, 67 and 74 degrees, which the main peaks indicated the iron oxide.
Conclusion: The purpose of this research was to analyze the magnetic property in the CMC biocomposite and then coat it on the surface of the paper. Therefore, the experiments were carried out in 2 stages. In the first stage, CMC magnetic biocomposite was made by in situ synthesis process with iron salts. In the second phase, handsheet was prepared by using commercial kraft fibers and coated ones. The results of the testing samples showed the successfully production of magnetic biocomposite. Also, the paper coated with this material has suitable magnetic properties.
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