• 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.

• 폴리머
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• 제25권6호
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• pp.848-854
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• 2001

무정형 고분자인 ethylene-methyl acrlate-glycidyl methacrylate 공중합체 (E-MeA-GMA)와 결정성 고분자인 poly(ethylene terephthalate) (PET)와의 블렌드에서 그라프트 반응에 따른 PET의 결정화 거동을 조사하였다. PET와 E-MeA-GMA간의 그라프트 반응 수준을 torque-rheometer, FT-IR, SEM을 이용하여 확인하였으며, 반응시간에 따른 결정화 거동 변화를 DSC와 광산란 방법을 이용하여 관찰하였다. 또한 라멜라 수준의 결정구조를 소각 X선 산란법을 이용하여 조사하였다.

• Fibers and Polymers
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• 제6권4호
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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.

• 폴리머
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• 제24권6호
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• pp.854-859
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• 2000

N,N-dimethylamino ethyl methacrylate(DMAEMA)와 poly(ethylene glycol) (PEG)로 이루어진 블록 공중합체를 합성하였고, 그 구조를 FT-IR, DSC, 및 $^1$H-NMR로 확인하였다. 준비된 poly(DMAEMA))-PEG 블록 공중합체 수용액에 poly(ethyl acrylamide)(PEAAm)를 첨가하면 블록 공중합체의 DMAEMA와 poly(EAAm) 사이에서 일어나는 수소결합에 의해 나노복합체가 형성되었다. 나노복합체는 임계미셀농도 이상의 농도에서 이루어졌다.

• 공업화학
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• 제1권2호
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• pp.147-153
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• 1990

소결공정에 의하여 tertiary amine을 함유하는 hydroxypropyl methacrylate 고분자막을 제조하였다. 이 막의 함수율은 수용액의 pH가 감소함에 따라 증가하였다. 인슐린의 투과도 역시 수용액의 pH가 감소함에 따라 증가하였다. 이 막의 투과도는 소결 압력이 증가함에 따라 감소하였다. 이 막에 당산화효소를 고정화시킨 acryl amide 막을 부착하여 복합 matrix device를 제조하였다. 이 막의 인슐린 투과도는 glucose의 농도가 증가함에 따라 증가하였다.

• Macromolecular Research
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• 제8권6호
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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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• 제28권9호
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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%.

• 한국응용과학기술학회지
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• 제4권1호
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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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• 제50권4호
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• pp.639-645
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• 2012

Isophorone diisocyanate, polycarbonate diol, dimethylol propionic acid를 출발물질로 하여 제조된 폴리우레탄 prepolymer의 미반응 NCO 기를 실란커플링제인 aminopropyl trietoxysilane (APS)로 capping시켜 수분산 폴리우레탄(waterborne polyurethane dispersion, PUD)을 합성하였다. 그 후 이 PUD에 아크릴 단량체인 2-hydroxyethyl methacrylate와 methyl methacrylate의 혼합물을 첨가하고 중합시켜 silylated acrylic polyurethane dispersion을 제조하였다. 동적 빛 산란법에 의해 측정된 silylated acrylic polyurethane dispersion의 평균 직경은 APS 첨가량이 증가됨에 따라 39.0 nm에서 399.8 nm로 크게 증가하였다. 또한 코팅 도막의 연필경도는 APS의 첨가량이 증가되면서 B에서 F로 향상되었다.

• 청정기술
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• 제12권1호
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• pp.19-25
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• 2006

본 연구에서는 폴리에테르 계열의 폴리올과 이소시아네이트 (2,4-toluene diisocyanate) 그리고 하이드록시 아크릴레이트 (hydroxypropyl methacrylae)를 이용하여 광경화가 가능한 우레탄 메타아크릴레이트 계열의 올리고머를 합성하였다. 합성된 우레탄 메타아크릴레이트의 색상, 점도, 굴절율과 같은 기본적인 물성과 광경화후 필름에 대한 인장 강도, 신율, 영율 등을 측정하였다. 광경화 속도는 Photo-DSC를 이용하여 측정하였다. 유사한 폴리올 구조 내에서는 폴리올의 분자량이 증가하면 인장 강도, 영율, 광경화 속도는 감소하고 연신율은 증가하는 결과를 얻었다. 우레탄 메타아크릴레이트 올리고머의 관능기 숫자가 증가하면 인장 강도, 영율, 광경화 속도는 증가하고 반대로 연신율은 감소하는 결과를 얻게 되었다.