• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.34-48
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• 2024

The objective of this study was to evaluate the safety of biodegradable mulching films in soybean (Glycine max) cultivation by measuring their effects on crop growth and yield, film decomposition and soil chemical and physical properties. In 2022 and 2023, plant height, branch number, chlorophyll contents, yield components, and yield of soybean did not vary significantly in areas using PE films and biodegradable mulching films. The light transmission rate of the biodegradable mulching films ranged from 6.4 to 15.8% when measured 112 days after soybean transplanting, and was higher, on average, in 2023 than in 2022. In both years, degradation of the biodegradable mulching films began 20 days after soybean transplantation and increased over time. In addition, remains of biodegradable mulching films were present in fields at soybean harvest and remained until 50 days after harvest. Decomposition rates of the biodegradable mulching films at 112 days after soybean transplanting ranged from 9.8 to 26.7% in 2022 and 13 to 36% in 2023. Although soil pH and EC varied based on the year and timing of measurements, there was no significant difference between areas that used biodegradable mulching films and PE films. Soil organic matter, nitrate and exchangeable cation contents such as Ca, Mg, and K were not significantly different in areas that used both PE films and biodegradable films. However, significantly higher levels of available phosphoric acid content were measured in areas that used biodegradable mulch films E, S, and T. Regardless of which films were used, there were no significant differences in the soil's physical properties. In 2022 and 2023, there was no difference between areas that used biodegradable mulch films and PE films. However, soil temperature in mulched areas was 2℃ higher and soil moisture was 5-15% higher than in non-mulched areas. Barley growth was not affected by being planted in soil that had been used for soybean cultivation with biodegradable films. Therefore, the biodegradable mulch films used in this study can be used without negatively affecting the growth, yield, and soil environment of soybeans.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.141-147
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• 2013

The simple and facile radiation technique of the preparation of antibacterial biodegradable polymer films containing silver nanoparticles (Ag NPs) was described. The biodegradable poly(butylene adipate-co-terephthalate) (PBAT) films containing silver trifluoroacetate (Ag TFA) were prepared by a solvent casting method, and then the films were irradiated by electron beams at the various doses ranging from 20 to 200 kGy to form Ag NPs in the biodegradable polymers. The results of UV-vis and FE-SEM/EDX analyses revealed that the Ag NPs were successfully formed in the PBAT matrix during the electron beam irradiation, and their amounts were dependant on the absorbed dose and Ag TFA concentrations. Furthermore, on the basis of the results of the antibacterial test through disk diffusion and colony counting test, the irradiated PBAT/Ag TFA films exhibited the antibacterial property due to the formation of Ag NPs.

• Journal of Applied Biological Chemistry
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• v.43 no.2
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• pp.79-85
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• 2000

Biodegradable films were prepared from roasted sesame meal and rice bran. Acetic anhydride, succinic anhydride, and formaldehyde were added to the film-forming solutions, and their effects on tensile strength, percent elongation, water vapor permeability, and water solubility of the films were studied. Roasted sesame meal did not form film without acylation or addition of formaldehyde. Acylated roasted sesame films had higher tensile strength and water-solubility, and lower % elongation than rice bran films. Acylation with acetic and succinic anhydrides increased tensile strength, percent elongation, and water solubility of rice bran films, but decreased water vapor permeability. Treatment with formaldehyde increased tensile strength of roasted sesame and rice bran films and % elongation of rice bran films, while reducing water-solubility of roasted sesame and rice bran films and water vapor permeability of rice bran films.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.2
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• pp.49-56
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• 2011

Mulching technique is used to control the temperature and moisture content of soil by covering the ground surface. Most kinds of mulching film are made of polyethylene which is non-biodegradable synthetic polymer. Utilizing these films has been one of the main sources in soil pollution. Thus residual films under the ground should be removed after a certain period of time. Therefore, an alternative mulching material made of biodegradable functional paper is considered instead of non-biodegradable films. The mulching sheet produced from paper basis has a functionality to be naturally degraded and then recycled to the bio-materials on soil. In this study, the paper based-mulching sheet coated with biodegradable polymer was specially produced using a laboratory bar coater. Coating colors prepared by dissolving PBS/PLA in chloroform were applied to kraft paper. The mechanical strength and aging properties of this mulching sheet were investigated. The burst strength of polymer-coated paper was decreased with the increase of the PBS ratio in PBS/PLA blends, and, in particular, 30/70 blending condition led to good stability in heat-aging atmosphere for 60 days.

• Journal of the Korean Applied Science and Technology
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• v.16 no.1
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• pp.67-73
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• 1999

Chitosan and Algin are known as a natural polymers. Biodegradable films were prepared by solution blend method in the weight ratio of natural polymer(low, medium, high-Chitosan, Algin) for the purpose of useful bioimplants. The possibility of bioimplants, which were prepared from natural polymers as a skin substitute and food wrapping materials were evaluated by measuring biodegradability. This biodegradable films were inserted in the back of rats and their biodegradability was investigated by hematological change evaluation as a function of time to biotransformation. It was found that these values of biodegradable films give some good results with short period test.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.48-53
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• 1998

Chitin is known as biodegradable natural polymer. But, in spite of various application of chitin from waste marine sources, commercial use of chitin has been limited due to highly resistance to chemicals and the absense of proper solvents. We made various viscosity of chitosan from chitin by change of Mima's method through the deacetylation which is various condition of NaOH concentration, reaction time and temperature. Also, Polyvinyl alcohol/chitosan blend films were prepared by different solution blends containing the ratio of 5, 10, 15 and 20% chitosan and low, medium, high molecular weight of chitosan to find a more useful biodegradable polymer. Thermal and mechanical properties of PVA/chitosan blend films such as DSC, impact strength, tensile strength and morphological changes by SEM were determined. The 10-15% PVA/chitosan(low, medium) blend films were similar to PVA. Also, PVA/chitosan blend films at the laboratory soil test(Pot Test) were completely degraded in month with four kinds of soils by microorganisms.

• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.90-96
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• 1999

Biodegradable films were prepared by solution blending method in the weight ratio of Chitosan and Algin for the purpose of useful bioimplants. The possibility of bioimplants, which prepared from natural polymers as a skin substitute and food wrapping materials were evaluated by measuring the biodegradability. these biodegradable films were inserted in the back of rats and their biodegradability was investigated by hematological change as a function of time. Rats study showed that low-Chitosan induced increments of monocyte and basophil after 48 hours of implantation. And medium-Chitosan showed increase of lymphocyte and decreased neutrophil counts after 48 hours of implantation. Low, medium Chitosan showed high hemoglobin contents, medium and high Chitosan showed high hematocrit value after 48 hours of implantation. As a result, medium, high-Chitosan induced potential incompatibility in the tissue after 48 hours, but there was little effects to the skin inflammation. The values of biodegradable films, which prepared from natural polymers measured in this study were some satisfiable results at short period with those of ideal skin bioimplants and artificial skin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.417-422
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• 1999

Algin and chitosan are known as biodegradable natural polymers. PVA is useful for the production of water soluble packaging, paper, textile sizes. PVA/Algin and PVA/chitosan films were prepared by solution blends method in the weight ratio of chitosan, algin for the purpose of useful biodegradable films. Thermal and mechanical properties of blend films such as DSC, impact strength, tensile strength and morphology by SEM were determined. As a result, The ratio of 10.0wt% PVA/chitosan films were similar to PVA at thermal and mechanical properties. PVA/Algin films were found that phase separation was occured as more than 25wt% increasing the blend ratio of algin. PVA/Algin films were observed to be less partially compatibility than 10wt% increasing the blend ratio of algin by DSC, mechanical properties and SEM. Blend films were completely degraded pH 4.0 better than 7.0, 10.0 in the buffer solution. Also, they were rapidly degraded in the enzyme( glucosidase) solution better than pH solution by enzymolysis.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.2
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• pp.75-81
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• 2010

Characteristics of mixing biodegradable polymers and polymer impregnated paper for mulching mat for seedling were investigated. The mixed film of 70% PLA was most easily biodegradable. The surface of polymer films were changed to more rough due to enzymatic degradation of lipase. Tensile strength and breaking elongation of PLA mixed films were increased to the 0.04-0.31 kN/m and the 0.17-0.96%, respectively. With higher PLA contents, intensities of ester originated carboxyl group(about $1,748cm^{-1}$) were increased. Physical properties of prepared mulching mats were increased with PLA contents and stiffness of mulching mat was not so much changed.

• Journal of the Korean Applied Science and Technology
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• v.15 no.4
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• pp.71-78
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• 1998

Gum is known as natural polymer. Biodegradable films were prepared by solution blend method in the weight ratio of natural gums(Xanthan, Locust bean, Guar) for the purpose of useful bioimplants. The possibility of bioimplants, which prepared from natural gums as a skin substitute was evaluated by measuring biodegradability. This biodegradable films were inserted in the back of rats and their of biodegradability were investigated by hematological change evaluation as a function of time to the biotransformation. Rats implantation test results showed that Guar induced increments of monocyte and basophil after 48 hours of implantation. And Locust bean showed increase of monocyte and neutrophile counts after 48 hours of implantation. And Xanthan induced decrease of monocyte and neutrophile at 24 hours after implantation. Guar and Locust showed high hemoglobin contents and hematocrit after 48 hours of implantation. Guar and Locust induced some suspects of incompatibility in the tissue after 48 hours, but three were little effects to the skin inflammation at 24 hours. These values of biodegradable films, which prepared from prepared from natural gums measured in this were some satisfiable results at short period with those of ideal skin bioimplants.