• Macromolecular Research
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• v.11 no.6
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• pp.418-424
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• 2003

Exfoliated poly(methyl methacrylate-co-styrene) [P(MMA-co-ST)]/silicate nanocomposites were synthesized through a multistep emulsion polymerization. The methyl methacrylate monomers were polymerized first and then the styrene monomers were polymerized. The nanocomposites had core-shell structures consisting of PMMA (core) and PS (shell); these structures were confirmed by $^1$H NMR spectroscopy and TEM, respectively. P(MMA-co-ST) copolymers showed two molecular weight profiles and two glass transition temperatures (T$_{g}$) in GPC and DMA measurements. At 30 $^{\circ}C$, the nanocomposites exhibited 83 and 91 % increases in their storage moduli relative to the neat copolymer because the silicate layers were dispersed uniformly in the polymer matrix.x.

• 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.

• Macromolecular Research
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• v.16 no.4
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• pp.293-302
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• 2008

In our previous publication, the problem of particle deformation and coagulation at the nucleation stage in the presence of cross-linker was intensely studied by seeded batch dispersion polymerization of methyl methacrylate (MMA). In the present work, highly cross-linked, monodisperse PMMA particles were prepared under various reaction conditions by seeded semi-continuous process. Monodisperse, $6.5{\mu}m$-diameter PMMA particles containing up to 8 wt% of DVB or EGDMA were successfully made by seeded semi-continuous process and multi-semi-continuous addition process, respectively. Therefore, this study shows that seeded semi-continuous process is more effective and efficient to prepare highly cross-linked, monodisperse particles than non-seeded and seeded batch processes.

• Polymer(Korea)
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• v.34 no.1
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• pp.38-44
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• 2010

Core-shell particles of inorganic/organic pair were synthesized from $CaCO_3$ absorbed sodium dodecyl benzene sulfonate(SDBS) surfactant. Shell components were synthesized by sequential emulsion polymerization. Various monomers were used as shell components such as methyl methacrylate(MMA), ethyl acrylate(EA), butyl acrylate(BA), and styrene(St). Ammonium persulfate(APS) was used as an initiator and 2-ethylhexyl acylate(2-EHA) was used as a functional monomer, In the $CaCO_3$/organic core-shell particle polymerization, $CaCO_3$ absorbed surfactant SDBS of 0.5 wt% was prepared first and then core $CaCO_3$ was encapsulated by emulsion polymerization. 0.1 wt% of APS was added sequentially to minimize the formation of new monomer particle during shell polymerization. The structure of inorganic/organic core-shell particles were characterized by measuring the decomposition degree of $CaCO_3$ using HCl solution, thermogravimetric analyzer, scanning electron microscope, and transmission electron microscope.

• Journal of Electrical Engineering and Technology
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• v.6 no.6
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• pp.836-841
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• 2011

Plasma polymerized methyl methacrylate (ppMMA) thin films were deposited by plasma polymerization technique with different plasma powers and subsequently thermally treated at temperatures of 60 to $150^{\circ}C$. To find a better ppMMA preparation technique for application to organic thin film transistor (OTFT) as dielectric layer, the chemical composition, surface morphology, and electrical properties of ppMMA were investigated. The effect of ppMMA thin-film preparation conditions on the resulting thin film properties were discussed, specifically O-H site content in the pMMA, dielectric constant, leakage current density, and hysteresis.

• Textile Coloration and Finishing
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• v.4 no.4
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• pp.81-89
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• 1992

Graft polymers of alginic acid-PMMA, different in composition and Mv of branched PMMA, were prepared by emulsion graft polymerization at various MMA concentrations. In aqueous dispersion solution, the adsorption of graft polymer on the montmorillonite was carried out to modify the surface property of powder, and the adsorption of PMMA in organic solvents (acetone, benzene) on the modified surface of powder were observed. The results obtained were as follows. 1. In emulsion graft polymerization of MMA on the sodium alginate in aqueous solution, SA conversion, MMA conversion and % grafting were increased with increasing MMA concentration where as graft efficiency was decreased. 2. The adsorption amount of graft polymer was increased with the elevation of temperature and the increased of dispersion concentration and with the increase of branched PMMA composition of graft polymer. 3. In organic solvent, the adsorption of PMMA on the surface modified particle was proceeded by the orientation along the stretched branched PMMA of adsorbed graft polymer which is in radial direction to the particle surface. 4. The adsorbed amount of PMMA was increased as the temperature and concentration of PMMA solution, the branching of adsorbed graft polymer and the solvency of solvent were increased.

• Textile Coloration and Finishing
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• v.30 no.4
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• pp.256-263
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• 2018

The binder polymers for digital textile printing(DTP) pigment inks were prepared using miniemulsion polymerization with various monomer compositions to study effects of monomer compositions on particle size distribution, average molecular weight, Tg, and color strength and rubbing fastness of the dyed fabrics with the prepared binder based pigment ink. The monomers used were MMA(Methyl methacrylate), BA(Butyl acrylate), MAA(Methacrylic acid), NMA(N-methylol acrylamide), NEA(N-ethylol acrylamide) and the ratios of the monomers were changed. The particle size was the smallest with 136nm when the MMA to BA weight ratio was 4:16 and the largest with 290nm when the MMA, BA, MAA, NEA ratio was 2.5:17:0.25:0.25. However, the glass transition temperature was lowest with $-41.90^{\circ}C$ and the color strength and rubbing fastness of the resulting sample were the best when the MMA, BA, MAA, NEA ratio was used. This suggested that the introduction of the NEA monomer to the binder polymer for the pigment ink could be an efficient way to enhance the rubbing fastness of the DTP pigment inks present.

• Korean Chemical Engineering Research
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• v.47 no.4
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• pp.470-475
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• 2009

To study the optimal synthesis conditions of aqueous acrylic adhesive using emulsion polymerization, the effects of monomer, surfactant and initiator on the adhesive properties, such as conversion rate, particle size, peel strength, and glass transition temperature, were investigated. 2-EHA, n-BA and MMA were used as main monomers, 2-HEMA and AAc as functional monomers, SLS as surfactant and APS as initiator, respectively. The conversion rate was over 95% at 3.75% surfactant(SLS/monomer), 0.612% initiator(APS/monomer) and $82^{\circ}C$ reaction temperature. When the excess amount of surfactant or initiator was used, the peel strength represented decreasing tendency. The maximum conversion rate and peel strength were obtained at 65% 2-EHA/monomer, 20% BA/monomer, and 10% MMA/monomer.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.87-92
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• 2002

At present, the polymer-modified mortars are used as high-performance as well as multi-functional materials in the construction industry. The purpose of this study is to synthesize polymer to modify in cement mortars and make test samples to understand pore size distribution. This paper deals with the effect of monomer ratio on the typical properties of polymer-modified mortars using Methylmethacrylate-Butyl Acrylate(MMA/BA) latexes synthesized through emulsion polymerization. From the results, we knew that the pore volume of polymer-modified mortars using Methylmethacrylate-Butyl Acrylate latexes at bound MMA contents of 70 and 60 percent is 7.5-75cm$^3$/g and the fine pore volume is increased with an increase in the polymer-cement ratio. The total pore volume of polymer-modified mortars using MMA/BA latexes is linearly reduced with an increase in the bound MMA content and increased in the polymer-cement ratio.

• Bulletin of the Korean Chemical Society
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• v.17 no.1
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• pp.16-19
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• 1996

The bulk photopolymerization of methyl methacrylate (MMA) with disilanes such as 1,2-diphenyldisilane and 2-phenyl-1,3-disilapropane was carried out to yield poly(MMA)s containing the corresponding disilyl moiety presumably as an end group. It was found that while the polymerization yields and the polymer molecular weights decreased as the relative disilane concentration increased, the TGA residue yields and the relative intensities of SiH IR stretching bands increased with increment of molar ratio of disilane over MMA. The photopolymerization of MMA with 2-phenyl-1,3-disilapropane produced higher-molecular-weight polymer with lower TGA residue yield when compared to the photopolymerization of MMA with 1,2-diphenyldisilane. The disilanes seemed to significantly influence on the photopolymerization as both chain initiation and chain transfer agents.