• Journal of Adhesion and Interface
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• v.9 no.1
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• pp.16-21
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• 2008

Hybrid emulsions consisting of polyurethane and acrylic polymer were prepared by emulsion polymerization of acrylic monomers and polyurethane water dispersions (PUD) as an emulsifier. At first, cationic type of PUD was synthesized with IPDI, PTMG1000, MDEA, and acetic acid. Then, acrylic monomers, such as MMA and n-BA, were copolymerized with the PUD without adding further surfactant. The tensile properties and water resistance increased with increasing acrylic monomer ratio. The hybrid emulsions showed better properties than the emulsions simply blended with the PUD and the acrylic emulsions.

• Journal of the Korea Institute of Building Construction
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• v.20 no.1
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• pp.35-41
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• 2020

The thin coating material used in the outer insulation finishing method is a finishing material mainly based on acrylic emulsion. In this study, the properties of silane modified acrylic emulsion and silica dispersed acrylic emulsion were evaluated. Experimental results showed that the silane modified acrylic emulsion had no significant effect on improving tensile strength, but was effective in improving the performance of adhesion strength, water absorption coefficient, and hot and cold repeat resistance. Silica-dispersed acrylic emulsions were effective in improving tensile strength, and at 10% substitution rate, they were effective in improving the performance of adhesion strength, water absorption coefficient and hot / cold resistance. Through this, it was judged that a composite emulsion capable of improving the performance of the acrylic emulsion could be prepared.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.133-134
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• 2019

As part of recent low-energy policies, thermal insulation standards for buildings are being tightened every year. The importance of external insulation methods is increasing due to the strengthening of insulation standards. Among the main materials used in the external insulation method, dry bit material is a finishing material composed of an organic binder and aggregate. When the fire occurs, the ignition of the surface part causes a direct fire on the thermal insulation material at the rear side when heat energy is concentrated. Therefore, it is important that the finishing material in dry insulation using a dry bit has a low fire spreading property in case of a fire and does not have a sustained combustion. The purpose of this study was to evaluate the fire spreadability by changing the internal fillers while using alkoxide-based acrylic emulsions, hybrid acrylic emulsions, and general acrylic emulsions in order to suppress the fire spreading properties of exterior finish materials.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.445-451
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• 2010

To prepare very stable acrylic type emulsion having a visible ray absorption property, in-situ preparation technique of $Cu_xS$ nanoparticle was adopted. Firstly, the acylic emulsions of methyl methacrylate(MMA), butyl acrylate(BA), and acrylonitrile(AN) were synthesized by pre-emulsion polymerization at $60^{\circ}C$ in the presence of anionic surfactant. Secondly, $Cu_xS$ nanocomposited emulsions were directly prepared in the prepolymerized acrylic emulsion with $CuSO_4$ at $50^{\circ}C$. The presnce of $Cu_xS$ nanoparticle in emulsion was confirmed by SEM and EDS. The final $Cu_xS$ nanocomposited emulsion showed an olive-green colour and good emulsion stability up to 1 month. In addition the PET films coated with our $Cu_xS$ nanocomposited emulsion absorbed effectively the visible ray.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.510-516
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• 1997

O/W emulsions were prepared by adding water to the solution containing amphiphilic resin and the mixed emulsifier of cetyl alcohol polyoxyethylene(20) sorbitan monooleate. Phase behavoir of these emulsions was studied at various HLB(Hydrophilic Lipophilic Balance) values and temperatures. The polar oil emulsion containing the amphiphilic resin showed improved phase stability at various temperatures. Model compounds which contain one of the functional groups in the amphiphilic resin were used in the polar oil phase in order to study the effect of interaction between the functional group and the emulsifier on the phase stability of emulsion. These model compound emulsions showed the phase stability order of poly(acrylic acid)

• Polymer(Korea)
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• v.36 no.2
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• pp.177-181
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• 2012

This study presents the preparation of double emulsions in a poly(dimethylsiloxane) (PDMS)-based microfluidic device. To improve the wettability of hydrophilic continuous phase onto a hydrophobic PDMS microchannel, the surface was modified with 3-(trimethoxysilyl) propyl methacrylate (TPM) and then sequentially reacted with acrylic acid monomer solution, which produced selective covalent bonding between acrylic acids and methacrylate groups. For the proof of selective surface modification, tolonium chloride solution was used to identify the modified region and we confirmed that the approach was successfully performed. When water containing 0.5% w/w sodium dodecyl sulfate and 1% w/w Span80 with hexadecane were loaded into the selectively modified microfluidic channels, we can produce stable double emulsion. Based on the spreading coefficients, we predict the morphology of double emulsions. Our proposed method efficiently produces monodisperse double emulsions having 48.5 ${\mu}m$(CV:1.6%) core and 65.1 ${\mu}m$ (CV:1.6%) shell. Furthermore, the multiple emulsions having different numbers of core were easily prepared by simple control of flow rates.

• Journal of the Korean Applied Science and Technology
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• v.25 no.4
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• pp.485-494
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• 2008

The acrylic coating emulsions were prepared by the emulsion polymerization to protect the surface of steel plate from the corrosion chemicals like acid, base and salt water. MMA(methyl methacrylate), styrene, BA(butyl acrylate), and 2-HEMA(2-hydroxyethyl methacrylate) were used as monomer. KPS(potassium persulfate) and SBS(sodium bisulfite) as redox initiator and SDBS(sodium dodecylbenzene sulfonate) as emulsifier were used on the emulsion polymerization reaction. The most stable in-situ coating was obtained when 10% of MMA was added. Both particle size and quantity in emulsion were decreased as increasing the mount of SDBS. the most stable prepared coating emulsion with polyisocyanate crosslinker showed very high anticorrosion properties on the coated steel layer to salt water, whereas no significant improvement of anticorrosion property to acdic and basic condition it showed.

• 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.

• Applied Chemistry for Engineering
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• v.17 no.2
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• pp.132-137
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• 2006

Polyurethane acrylate hybrid emulsions were prepared by seeded polymerization techniques. In the synthesis, seeded polyurethane dispersion containing a carboxylic group was used to endow hydrophilicity to the hybrid emulsion and various acrylates such as methyl methacrylate (MMA), 2-hydroxy ethylmethacrylate (2-HEMA), n-butyl acrylate (n-BA) and acrylic acid (AAc) were used to endow hydrophobicity. The particle size and distribution of various emulsion particles such as polyurethane acrylate hybrid emulsion, polyurethane dispersion homopolymer, acrylate emulsion, and physical blending emulsion were measured by a particle size analyzer. The average particle size of hybrid emulsion was greater than physical blending emulsion. And tensile strength, 100% modulus, elongation, and swelling properties of the polyurethane acrylate hybrid emulsion were studied and compared with those of polyurethane homopolymer, acrylate emulsion, and physically blended compositor, respectively. To improve chemical and physical resistance, this paper review a melamine hardener and compares it for effects on the physical properties of cured coating.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2004.07a
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• pp.19-42
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• 2004

Sizing properties in paper are generally developed through the application of both internal and surface sizes. Rosin, wax, and synthetic sizes including ASA, AKD, and stearic anhydride are and have been used to provide wet-end sizing to paper. In many cases, the use of some of these sizes leads to runnability problems that are inherent in the wet-end operation. Variability in furnish, fines, broke, filler, water chemistry, conductivity, and pH control impacts the wet-end operation. Size press chemicals including starch and polymers such as styrene-acrylic, styrene-maleic, and styrene acrylate emulsions are used in conjunction with internal sizes to improve the paper surface for printing and strength properties, porosity, and opacity improvement. This paper will discuss results from a new, proprietary formulation and process that allows application of sizing chemistry more totally at the size press with reduced emphasis on wet end sizing. Runnability issues are thus minimized at the wet-end, chemical usage is more efficient, and significant cost savings can be realized. Case histories will be presented illustrating the advantages of this new application in commercial trials.