• Macromolecular Research
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• 제11권6호
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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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• 제13권2호
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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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• 제16권4호
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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.

• Journal of Electrical Engineering and Technology
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• 제6권6호
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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.

• 폴리머
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• 제34권1호
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• pp.38-44
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• 2010

탄산칼슘/유기계 core-shell 입자를 제조하기 위해 core로는 침강성 탄산칼습을 사용하였고, shell로서는 여러 종류의 methyl methacrylate(MMA), ethyl acrylate(EA), n-butyl acrylate(BA), styrene(St), 2-ethylhexyl acylate(2-EHA)을 사용하여, 반응 온도 유화제, 개시제의 종류와 첨가량을 변화시킨 후에 유화중합을 시켜 최적의 유화중합 조건을 구하였다. 생성된 core-shell 입자의 구조는 FT-IR로, 입자크기와 형태는 입도 분석, SEM, TEM으로 각각 측정하였다. 그리고, 이 core-shell 입자에 부직포를 함침시켜 처리전후의 표면변화는 접촉각으로 확인하였다. 또한, 함침 처리 전후의 부직포/부직포 소재와 관능성 단량체 첨가한 부직포/부직포 소재의 박리 접착강도를 측정하여 상호 비교하였다. 탄산칼슘/유기 core-shell 입자 합성의 경우에는 유화제인 SDBS를 0.5 wt% 첨가한 탄산칼슘을 core로 하여 MMA와 0.1 wt% 농도의 APS를 단계적으로 주입하여 중합함으로써 탄산칼슘입자 표면에 단량체의 중합이 잘 유도될 수 있었으며 중합 도중에 새로운 중합체 입자의 생성이 적었다.

• 한국염색가공학회지
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• 제4권4호
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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.

• 한국염색가공학회지
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• 제30권4호
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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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• 제47권4호
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• pp.470-475
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• 2009

본 연구에서는 유화중합을 이용한 수분산성 아크릴계접착제의 최적의 합성조건을 구하기 위하여 주단량체로 2-EHA(2-ethylhexyl acrylate), n-BA(n-butyl acrylate), MMA(methyl metacrylate), 기능성단량체로 2-HEMA(2-hydroxylethylmethacrylate), AAc(acrylic acid), 유화제로는 음이온성 유화제인 SLS(Sodium Lauryl Sulfate), 그리고 개시제로 APS(Ammonium persulfate)를 사용하여 전환율, 입자 크기, 박리강도, 유리전이온도에 대한 유화제, 개시제, 단량체 함량의 영향을 고찰하였다. 반응온도 $82^{\circ}C$, 유화제(SLS/monomer) 3.75%, 개시제(APS/monomer) 0.612%에서 95% 이상의 전환율을 얻을 수 있었고, 유화제나 개시제의 양이 너무 많을 때는 박리접착강도가 감소하는 경향을 보였으며, 65% 2-EHA/monomer, 20% BA/monomer, 10% MMA/monomer에서 최대 전환율과 최대 박리접착강도를 얻을 수 있었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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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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• 제17권1호
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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.