• Microbiology and Biotechnology Letters
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• v.22 no.5
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• pp.491-494
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• 1994

Antibiotic HS-2 was purified from the culture broth of Streptomyces plicatosporus which was isolated from soil, by solvent extraction, silica gel column chromatography and gel filtration. Through the analysis of UV, $^{1}$H-NMR, $^{13}$C-NMR spectrum, HS-2 was identified as rubiginone B$_{2}$. It was confirmed that HS-2 enhanced the cytotoxicity of colchicine against multidrug-resistant tumor cells.

• Applied Chemistry for Engineering
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• v.26 no.2
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• pp.159-164
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• 2015

Pigment yellow 180 (P.Y.180), a kind of benzimidazolone, has been widely used in various industrial fields of ink, paint, plastics, toner, and color filter, etc. This is a high performing pigment that is a greenish yellow shade with excellent properties such as heat resistance, solvent resistance, acid resistance and alkali resistance. In this study, pigment compounds were synthesized using various coupling reaction temperature condition. The properties of samples crystallized under various solvents and temperature conditions using autoclave pressurizer were also investigated. The pigment crystallized using DMSO solvent treatment showed the improvements such as the increase of X-ray intensity ratios and particle size, high color strength, and enhanced dispersibility.

• Proceedings of the Korean Fiber Society Conference
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• 2007.11a
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• pp.239-240
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• 2007

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.148-151
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• 2004

The development of the gas separation processes using polymeric membranes has attracted a great deal of interest during the last two decades. Membrane in this application has to offer an excellent thermal stability, chemical/solvent resistance, and mechanical strength under operating conditions.(omitted)

• Journal of Adhesion and Interface
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• v.24 no.1
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• pp.17-25
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• 2023

In this study, waste polyethylene terephthalate (PET) was recycled to produce a support and then polyetherimide (PEI) was used for environmentally friendly organic solvent nanofiltration. The prepared composite membrane was first prepared by electrospinning a PET support, then casted on the support using PEI having excellent solvent resistance, and organic solvent nanoparticles using a Non-solvent Induced Phase Separation (NIPS) method. A filtration membrane was prepared. First, the fiber diameter and tensile strength of the PET scaffold prepared prior to membrane fabrication were identified through morphology analysis, and the optimal scaffold for the organic solvent nanofiltration membrane was identified. Afterward, the PET/PEI composite membrane prepared was checked for the DEA removal rate of Congo red having a molecular weight of 697 g/mol in ethanol to understand the performance as an organic solvent nanofiltration membrane according to the concentration of PEI. Finally, the removal rate of Congo red was 90% or more.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.5
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• pp.519-525
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• 2005

An electrochemical evaluation on the corrosion resistance for heavy anticorrosive paint(DFT:25um) was carried out for 5 kinds of heavy anticorrosive paints such as high solid epoxy(HE), solvent free epoxy(SE). tar epoxy(TE), phenol epoxy(PE). and ceramic epoxy(CE). Corrosion current densities obtained by Tafel extrapolation method from anodic and cathodic polarization curves didn't correspond with the values obtained by AC impedance measurement, however, the values of polarization resistance obtained from the cyclic voltammogram showed a good tendency corresponding well with the values of AC impedance measurement. Futhermore there was a good correlation against the corrosion resistance evaluation between passivity current density of the anodic polarization curve and diffusion limiting current density of the cathodic polarization curve. And corrosion resistance increased with corrosion potential shifting to noble direction. From the results discussed above. HE and CE had a relatively good corrosion resistance than other heavy anticorrosive paints.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.623-630
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• 2015

Prepared polyurethane resin for buffalo leather coating on surface was synthesized with addition reaction glycerol which had different mole ratio. Mechanical properties of the synthesized polyurethane resin were measured by the SEM, FT-IR, UTM. Growing concerns in the evnironment-friendly polymer resin, we have synthesized low late obtained solvent water dispersion resin to be coating on buffalo leather. The increase of aliphatic trihydric alcohol glycerol mole %, abrasion resistance and tensile strength had demonstrated reduce properties. On the contrary, elongation and flexibility properties had highly increased. In the result of toluene solvent resistance, there was no effect of increased or decreased by the ratio of glycerol mole %.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.100-107
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• 2015

Prepared polyurethane resin for vegetable leather coating on surface was synthesized with glycerol which had different mole ratio. Mechanical properties of the synthesized polyurethane resin were measured by the SEM, FT-IR, UTM. Growing concerns in the evnironment-friendly polymer resin, we have synthesized low late obtained solvent water dispersion resin to be coating on vegetable leather. The increase of aliphatic trihydric alcohol glycerol mole %, abrasion resistance and tensile strength had highly stronger in intensity and longer durability. On the contrary, demonstrated reduce properties of elongation and flexibility. In the result of toluene solvent resistance, there was no effect of increased or decreased by the ratio of glycerol mole %.

• Journal of the Korean Applied Science and Technology
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• v.27 no.2
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• pp.188-195
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• 2010

In this study, we experimented that how to synthesis waterborne urethane-acrylic hybrid resin for leather coatings. First of all, We had analyzed data by FT-IR, SEM and TGA for the machanical properties. By TGA analysis polymers showed heat distortion temperature. and by FT-IR measurement we confirmed that synthesis of urethane and acrylic. In the experiment, solvent resistance, polyurethane and acrylic grades 4-5 showed both a high. Tensile strength measured in the waterborne polyurethane > Acrylic emulsion showed strength in the order. Films were obtained by coating the water born resin on leveled surfaces and allowing them to dry at room temperature for 72hrs. After demolding, the films were kept in a desiccator to avoid moisture contant at $25^{\circ}C$ for 45hrs before the measurements. In this result, the mechanical propersies of waterborne polyurethane-acrylic hybrid resin showed that how effect to resin in leather coating between polyurethane content and acrylic content. Therefore, acrylic emulsion had most high solvent resistance glade and waterborne polyurethane had good result in abrasion test and tensile strength.

• Macromolecular Research
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• v.14 no.1
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• pp.1-33
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• 2006

Polyimides (PIs) exhibit excellent thermal stability, mechanical, dielectric, and chemical resistance properties due to their heterocyclic imide rings and aromatic rings on the backbone. Due to these advantageous properties, PIs have found diverse applications in industry. Most PIs are insoluble because of the nature of the high chemical resistance. Thus, they are generally used as a soluble precursor polymer, which forms complexes with solvent molecules, and then finally converts to the corresponding polyimides via imidization reaction. This complexation with solvent has caused severe difficulty in the characterization of the precursor polymers. However, significant progress has recently been made on the detailed characterization of PI precursors and their imidization reaction. On the other hand, much research effort has been exerted to reduce the dielectric constant of PIs, as demanded in the microelectronics industry, through chemical modifications, as well as to develop high performance, light-emitting PIs and liquid crystal (LC) alignment layer PIs with both rubbing and rubbing-free processibility, which are desired in the flat-panel display industry. This article reviews this recent research progresses in characterizing PIs and their precursors and in developing low dielectric constant, light-emitting, and LC alignment layer PIs.