• Polymer(Korea)
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• v.30 no.3
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• pp.230-237
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• 2006

Copolymers(HSA-98-20, HSA-98-0, HSA-98+20) which we acrylic resin containing 80% solid content were synthesized by the reaction of monomers, including methyl methacrylate, n-butyl acrylate, and 2-hydroxyethyl acrylate with a functional monomer, acetoacetoxyethyl methacrylate (AAEM), which nay give improvements in cross-linking density and physical properties of films. The physical properties of prepared acrylic resins, containing AAEM, are as follows viscosities, $1420\sim5760cps$ ; number average molecular weight, $2080\sim2300g/mol$; polydispersity index, $2.07\sim2.19$ ; and conversions, $88\sim93%$. In the next step, high-solid coatings (HSA-98-20C, HSA-98-0C, HSA-98+20C) were prepared by the curing reaction between acrylic resins containing 80% solid content and isocyanate at room temperature. Various properties were examined on the film coated with the prepared high-solid coatings. The introduction of AAEM to the coatings enhanced the abrasion resistance and solvent resistance, which indicated the possible use of high- solid coatings for top-coating materials of automobile. Since the curing by viscoelastic measurement occurred in sequence of HSA-98+20C > HSA-98-0C > HSA-98-20C, it was concluded that the curing rates became faster with incresing $T_g$ values.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1741-1746
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• 2010

This study is on development of UV-cured anti-stain coating compounds which have more improved anti-stain function to prevent a surface of PVC tile from stain. To make an anti-stain coating composition, water soluble antistatic agent made from ammonium(IV) salt, antistatic agents for acrylic and polyurethane were used. Their contents varied from 5 to 20wt% against quantities of resin in coating composition. After coating PVC tiles using bar-coating method that can adjust a thickness, we estimated surface properties of coated layer such as anti-stain, electric resistance, adhesive power, thickness of coating, and so on. Results showed that a coating composition added 15wt% of water soluble antistatic agent and coated with No.12 bar-coater had the optimum surface property in electric resistance($3.24{\times}10^9{\Omega}/cm^2$), anti-stain(ink Test, Dust Test) and adhesive power. We could also find electric resistance and anti-stain effect were improved as antistatic agent content increased. However, excessive addition of antistatic agents(over 20wt%) caused the migration.

• Journal of Korean Society of Steel Construction
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• v.28 no.2
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• pp.97-108
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• 2016

Thermally sprayed metals or organic coatings is often used in corrosion protection of steel structures. Duplex coating systems of thermally sprayed metal in combination with organic coating are selected as a new generic type of coatings on steel structures under the highly corrosive environments. In this study, three types of corrosion tests were carried out on four types of thermal sprayed specimens with sealing: zinc, zinc-15%aluminum alloy, aluminum and aluminum-5%magnesium alloy, four types of duplex coated specimens; thermally sprayed metals in combination with paint of acrylic urethane, and painted specimens. NORSOK M-501, Wet/dry cyclic seawater tests and outdoor exposure tests of nine types of specimens were conducted. From the corrosion test results, weathering performance of them were presented.

• Journal of Environmental Health Sciences
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• v.36 no.3
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• pp.236-246
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• 2010

In preparative anti-corrosive coating experiments, polyaniline was obtained by reacting an oxidizing agent with the monomer aniline. Further, the primer coating was prepared using a variety of widely-used materials such as urethane resin. For the top coating, epoxy resin and acrylic urethane resin were used. Characteristics of the coatings were assessed according to KS and ASTM specifications, and the structure of the polyaniline was characterized using FT-IR and TGA. For analysis of anti-corrosive properties in salt-spray experiments, measurements of the oxidation state of iron and surface atomic analysis were conducted using XPS and SEM-EDX. Unlike general anti-corrosive coatings which exhibit anti-corrosive effects only as a primer coating, the anti-corrosive coatings using polyaniline as the anti-corrosive pigment showed a marked synergistic effect with the top coatings. In other words, the top coatings not only produce a fine view effect, but also increase, through interaction with the primer coatings, the resistance to diffusion of corrosive factors from the external environment. It was also found that, unlike the heavy metal oxide-forming layer of the passive barrier alone, the polyaniline anti-corrosive pigment oxidized iron at the interface with the iron substrate to form a passive barrier in the oxidic layer, and itself formed a potential barrier layer with anti-corrosive factors from the external environment. Although the passive layer was damaged, the damaged area did not become completely oxidized iron; on the contrary, it showed a tendency to reduction. This can be interpreted such that a passive layer is formed again on the damaged area, and that at the same time there is a tendency to self-healing.

• Journal of the Korean GEO-environmental Society
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• v.12 no.11
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• pp.51-57
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• 2011

The calcium hydroxide($Ca(OH)_{2}$) which is flowed into the deteriorated tunnel by groundwater is reacted with carbon dioxide($CO_{2}$) and the vehicle's exhaust gas ($SO_{3}$). So its by-products are precipitated at the drainage pipe and these cause the drainage clogging. Most by-products are composed of $CaCO_{3}$ with calcite from a chemical experiment. The purpose of this study is mainly focused on comparison of attachment on each material of drainage pipe (teflon-coated steel pipe, silicon-Oil coated pipe, acrylic pipe and PVC pipe). The test was progressed to disembogue the CaO aqueous solution and tunnel outflow into each of the pipes. The experimental results show that the most produced scale pipe is PVC material and the followings are Acrylic pipe, Silicon-Oil coating pipe and Teflon coating pipe. But the long-term test results showed that teflon-coated steel pipe had a problem with durability because soil which was contained in the tunnel outflow occurred detachment of coating and corrosion of the steel pipe.

• Journal of Adhesion and Interface
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• v.11 no.4
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• pp.137-143
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• 2010

Glass beads (GBs) were modified via plasma polymerization coatings in order to enhance the adsorption of polycyclic aromatic hydrocarbons (PAHs) in cigarette smoke and activated carbons (ACs) were also utilized for comparative purposes. First, GBs and ACs were subjected to surface modification via plasma polymerization coating of acrylic acid, acrylonitrile, 1,3-diaminopropane, thiophene or dimethylphosphite with a RF plasma (13.56 MHz) generator. Next, their adsorption behavior was evaluated with a home-made 4-port smoking machine by collecting the total particulate matters (TPMs) on a Cambridge filter pad, followed by the separation of PAHs via solid phase extraction and analysis with GC/MS. Finally, the plasma polymerization coatings were analyzed by FT-IR/ATR to elucidate the adsorption mechanism, while the topology of the modified GBs and ACs were studied by FE-SEM.

• Journal of Technologic Dentistry
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• v.31 no.4
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• pp.15-23
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• 2009

The aim of this study was to evaluate the bond strength of using a Au bonding agent applied on cp-Ti and nonprecious metal-gold-ceramic system. Metallic frameworks(diameter: 5mm, height: 20mm)(N=56, n=7per group) cast in Ni-Cr alloy, Co-Cr alloy and cp-Ti were obtained using acrylic templates and airborne particle abraded with $110{\mu}m$ aluminum oxide. Au bonding agent was applied on wash opaque firing as intermediate layer. SEM and SEM/EDS line profile were performed on the cutting the cross-section of the metal substrate-porcelain with intermediate Au coating. Groups were tested using shear bond strength(SBS) testing at 0.5mm/min. The mean SBS values for the ceramic-Au layer-metal combination were significantly higher than those ceramic-metal combination. While ceramic-Au layer-cp-Ti combinations failed to increase bond strength instead of using a titanium bonding porcelain. The appication of using Au intermediate layer significantly improve the bond strength combination with metal-ceramic system.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.113-120
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• 2008

This study was performed to develop environmentally-friendly finishing materials for construction. In order to abate formaldehyde and ammonia in indoor air, liquid coating agents for indoor finishing were formulated with bamboo charcoal powder, cypress extracted water, and water-borne acrylic binder. Deodorization rate, far-infrared ray emission rate, anions emission amount, and anti-bacterial effect were investigated. Deodorization rate was increased as cypress extracted water content increased. Deodorization rates of the coating agents were 60.0~98.6% on formaldehyde and 76.7~86.2% on ammonia. No differences on far-infrared ray emission rate, anions emission amount, and anti-bacterial effect were found depending on different formulations. A 91.7% of far-infrared ray emission rate, 77 ea/cc of anions emission amount, and 99.4% of anti-bacterial effect were detected for all formulations. More effective application method of the coating agents revealed was a spray-gun. A $0.66kg/m^2$ of coating agent with a spray-gun and $0.94kg/m^2$ of coating agent with a brush was consumed each.

• Journal of Adhesion and Interface
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• v.8 no.1
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• pp.8-14
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• 2007

Poly(urethane-methyl methacrylate) hybrid emulsions can be controlled with their thermal, mechanical and anti-chemical properties as plastic coating materials. In this study, water dispersed poly(urethane-methyl methacrylate) hybrid emulsions were prepared by prepolymer synthesis and soap free emulsion polymerization. For imparting hydrophilicity on polyurethane prepolymer, 2,2-bis (hydroxymethyl) propionic acid was added to the polyurethane prepolymer with methyl methacrylate monomer and was neutralizated by triethylamine (TEA). After neutralization, the prepolymer mixture was dispersed in the water phase with stable droplets. The synthesis was carried out with chain extension from the ethylene diamine and initiation of methyl methacrylate by soap free emulsion polymerization. Stable poly(urethane-methyl methacrylate) hybrid emulsion was successfully obtained with different synthetic conditions and acrylic monomer contents. Poly(urethane-methyl methacrylate) hybrid emulsion were characterized and compared with tensile strength, viscosity, and adhesion properties.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.3
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• pp.285-288
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• 2020

The demand for coating technology on electric power equipment that has arisen from such issues regarding the attaching of illegal advertisements and posters to electric power distribution boxes such as TR, SW, etc. in down town areas seeks to produce functional coating surfaces using polymers and nano-materials that will result in improvements in self-cleaning performance and greater stability even under harsh environmental conditions. KEPCO-coatings consist of copolymerized acrylic resin and methacryl-modified reactive silicone that are able to chemically combine, which results in performance improvement without any leakage of of silicone, thus contributing to its properties of high-stability. Thus, the research team has also started long-term on-site testing on 9 electric power distribution spots around a city center in cooperation with the KEPCO Daeduck-yusung branch. The KEPCO-coating technology could advance the best coating materials and processes to meet appropriate circumstances for a variety of outdoor damage environment. It is also predicted that KEPCO could be possible to expand international electric maintenance markets and to arrange business platforms if KEPCO would achieve its original technology (IPs) by the means of upgrading in self-cleaning coating technology and obtaining long-term on-site test records from nationwide electric facilities.