• Macromolecular Research
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• v.13 no.2
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• pp.102-106
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• 2005

Poly(methyl methacrylate) (PMMA)/sodium montmorillonite (Na-MMT) nanocomposites were prepared with a novel method utilizing a macroazoinitiator (MAI). To induce the intergallery polymerization of methyl methacrylate (MMA), the MAI containing a po1y(ethylene glycol) (PEG) segment was intercalated between the lamellae of Na-MMT and swelled with water to enhance the diffusion of MMA into the gallery. The structure of the nanocomposite was examined using X-ray diffraction and transmission electron microscopy, and the thermal properties were examined using differential scanning calorimetry and thermogravimetry. The PMMA/Na-MMT nanocomposite prepared by intergallery polymerization showed a distinct enhancement of its thermal properties; an approximately $30^{\circ}C$ increase in its glass transition temperature and an $80\sim100^{\circ}C$ increase in its thermal decomposition temperature for a $10\%$ weight loss.

• Polymer(Korea)
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• v.25 no.6
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• pp.848-854
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• 2001

The crystallization behavior of poly (ethylene terephthalate) (PET) /ethylene-methyl acrylate-glycidyl methacrylate copolymer (E-MeA-GMA) blend was studied. The extent of reaction and the reaction rate between PET and E-MeA-GMA were measured with torque rheometer, FT-IR and SEM. The effects of the grafting reaction on the crystallization behavior were investigated with DSC and time-resolved light scattering (TR-LS) techniques. The morphological change at the lamellar level was also examined by using a small angle X-ray scattering (SAXS) method.

• Fibers and Polymers
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• v.6 no.4
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• pp.277-283
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• 2005

In order to prepare high molecular weight poly(methyl methacrylate) (PMMA)/silver nanocomposite microspheres, methyl methacrylate was suspension-polymerized in the presence of silver nanoparticles at low temperature with 2,2'-azobis(2,4-dimethylvaleronitrile) as an initiator. The rate of conversion was increased by increasing the initiator concentration. When silver nanoparticles were added, the rate of polymerization decreased slightly. High monomer conversion (about $85\%$) was obtained in spite of low polymerization temperature of $30^{\circ}C$. Under controlled conditions, PMMA/silver microspheres with various number-average degrees of polymerization (6,000-37,000) were prepared. Morphology studies revealed that except for normal suspension microspheres with a smooth surface, a golf ball-like appearance of the microspheres was observed, due to the migration and aggregation of the hydrophilic silver nanoparticles at the sublayer beneath the microsphere's surface.

• Polymer(Korea)
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• v.24 no.6
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• pp.854-859
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• 2000

The synthesis of poly(N,N-dimethylamino ethyl methacrylate (DMAEMA)-block-poly(ethylene glycol) (PEG)) copolymer has been carried out and the block copolymer was characterized by FT-IR, DSC, and $^1$H-NMR. The formation of polymeric nanoaggregation was observed in the solution mixture of poly(DMAEMA) -block-PEG copolymer and poly (ethyl acrylamide) (EAAm) due to the intermolecular interaction via hydrogen bond between DMAEMA and poly(EAAm). The formation of polymeric nanoaggregation was observed above critical micelle concentration (CMC).

• Applied Chemistry for Engineering
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• v.1 no.2
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• pp.147-153
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• 1990

Poly(hydroxypropyl methacrylate) membranes and matrix devices having tertiary amine moiety were prepared by sintering method, and their permeation characteristics were investigated. The water content of this membrane was increased with decreasing the pH of the medium. The permeability of this membrane was increased with decreasing the sintering pressure. Using sintered matrix device 'burst effect' was found at the early stage, and initial insulin release of glucose oxidase immobilized matrix device could be controlled by glucose concentration of the solution.

• Macromolecular Research
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• v.8 no.6
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• pp.292-297
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• 2000

The theoretical synthesis of the isotactic and syndiotactic poly(methyl methacrylate) were carried out as a model for real polymerization reactions following the normal chain reaction processes by repeating the uniform localization of wave functions with inclusion of the interaction between the end group of the cluster and an attaching molecule by the elongation method, and then, the calculated value was compared with the usual PM$_3$ calculation. The results revealed that a reaction of cluster with monomer molecules has made it possible to calculate the electronic structure and total energy of polymer with nearly infinite length and a matrix of constant dimension. The isotactic poly(methyl methacrylate) is more stable than syndiotactic one. The same tendency have been found between the experimentally measured properties and a calculated total energy to explain the chain motion in isotatic and syndiotactic poly(methyl methacrylate).

• Bulletin of the Korean Chemical Society
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• v.28 no.9
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• pp.1493-1498
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• 2007

In this work, alkyl methacrylate-based microgels were synthesized by an experimental design method, and their sebum absorption characteristics were investigated. The results of fractional factorial experimentation indicated that the cross-linking agent content, solvent content, and stirring speed were the main parameters in the synthesis of the microgels. The suitable synthesis conditions were determined by the response surface design method. Through a study of the monomer and solvent effects, it was confirmed that the microgel shows the highest sebum absorption ratio when t-butyl methacrylate is used as a monomer or when acetone is used as a solvent. The optimal microgel synthesis conditions for cosmetic application were determined, and the resulting microgel had a mean particle size of 4.7 μm and a sebum absorption ratio of 435%.

• Journal of the Korean Applied Science and Technology
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• v.4 no.1
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• pp.67-71
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• 1987

The transesterification reaction between diethanolamine and methyl methacrylate was kinetically investigated in the presence of various metal acetate catalysts at $120^{\circ}C$. The amount of reacted methyl methacrylate was measured by gas chromatography and liquid chromatography, and the reaction rate also measured from the amount of reaction products and reactants under each catalyst. The transesterification reaction was carried out in the first order with respect to the concentration of diethanolamine and methyl methacrylate, respectively. The over-all order is 2nd. The apparent rate constant was found to obey first-order kinetics with respect to the concentration of catalyst. The maximum reaction rate was appeared at the range of 1.4 to 1.6 of electronegativity of metal ions and instability constant of metal acetates.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.639-645
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• 2012

Waterborne polyurethane dispersion (PUD) was synthesized by capping the NCO groups of polyurethane prepolymers, prepared from isophorone diisocyanate, polycarbonate diol and dimethylol propionic acid, with aminopropyl triethoxysilane (APS). Subsequently, silylated acrylic polyurethane dispersion was synthesized by reacting the PUD with the mixture of acrylate monomers, 2-hydroxyethyl methacrylate and methyl methacrylate. The average particle size of silylated acrylic polyurethane dispersion, measured by the dynamic light scattering method, was increased from 39.0 nm to 399.8 nm by increasing the addition amounts of APS. Also, the pencil hardness of coating films of silylated acrylic polyurethane dispersion was enhanced from B grade to F grade with increasing APS content.

• Clean Technology
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• v.12 no.1
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• pp.19-25
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• 2006

In this study, photo-cuarable urethane methacrylate oligomers were synthesized from polyether type polyol (PP series, GP series), isocyanate (2,4-toluene diisocyanate) and hydroxy acrylate (hydroxypropyl methacrylate). We measured basic property including color, viscosity and refractive index of resulting urethane methacrylate. Also we measured tensile strength, elongation, and Young's modulus after photo curing. Photo curing speed was investigated using photo-DSC (TA instrument). In the case of similar polyol structure, as the molecular weight of polyol is increased, tensile strength, Young's modulus, curing rate were decreased, but elongation was increased. As the number of functionality of urethane methacrylate oligomer is increased, tensile strength, Young's modulus, curing rate were increased, but elongation was decreased.