• Macromolecular Research
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• 제13권5호
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• pp.418-426
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• 2005

One-pack cross-linkable nanocomposites of waterborne methyl ethyl ketoxime (MEKO)-blocked aromatic polyurethane dispersion (BPUD) reinforced with organoclay (quaternary ammonium salt of Cloisite 25A) were synthesized by the acetone process using 4,4'-methylenedi-p-phenyl diisocyanate (MDl), poly(tetramethylene) glycol (PTMG), dimethylol propionic acid (DMPA), and methyl ethyl ketoxime (MEKO). Particle size, viscosity, and storage stability of these nanocomposites were investigated. TEM and XRD studies confirmed that the silicate layers of organophilic clay were exfoliated and intercalated at a nanometer-scale in the BPUD matrix.

• Macromolecular Research
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• 제15권5호
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• pp.443-448
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• 2007

To improve the sound damping effect of flexible polyurethane foam, with an open-cell structure, various plate-like fillers, such as bentonite, organophilic clay and sodium montmorillonite intercalated with poly(ethylene glycol), were incorporated for the creation of nanocomposites. The plate-like fillers effectively improved the sound damping within the high frequency range. The structures of the nanocomposites and foam were examined using X-ray diffraction and scanning electron microscopy. The mechanical properties and flammability of the foams were also examined.

• 공학논문집
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• 제6권2호
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• pp.119-124
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• 2004

본 연구에서는 양이온교환방응에 의해 몬모릴로나이트 층 내의 금속 양이온을 긴 알킬 사슬을 갖는 유기 양이온으로 치환시켜 물성이 전혀 다른 유기 점토화합물인 몬모릴로나이트 층간 화합물을 합성한 후, 이 층간화합물을 증류수, 메탄올, 아세톤, 에테를 및 아세토니트릴 등과 같은 상이한 팽윤액체와 반응시켜 팽윤거동에 대하여 연구하였다. 특히 연구에 사용된 점토로는 한국산과 터키산의 두 가지 상이한 몬모릴로나이트를 선정하여 두 점토의 층간화합물 및 팽윤거동에 대하여 비교.분석하였다.

• 폴리머
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• 제25권2호
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• pp.263-269
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• 2001

나트륨 몬모릴로나이트($Na^{+}$-MMT)의 양이온을 3-(methacryloyl amino) propyl trimethyl ammonium chloride (MAPTAC)와 교환반응시켜 몬모릴로나이트의 표면을 친유성으로 개질시키는 동시에, 단량체와 공중합을 할 수 있는 이중결합이 부착된 MAPTAC-MMT를 제조하였다. 상온에서 MAPTAC-MMT가 분산된 수용액에서 N-isopropyl acryl amide (NIPAM)를 중합하여 열응답성 나노복합재료(PNIPAM-MMT)를 제조하였다. MAPTAC-MMT으로부터 제조된 열응답성 나노복합재료는 열응답성 고분자인 poly(N-isopropyl acrylamide) (PNIPAM)와 마찬가지 하한임계용액온도(LCST)를 나타내었으며, MAPTAC-MMT의 양이 증가함에 따라 PNIPAM-MMT의 LCST는 감소하였다. 또한 TGA실험 결과에서 열응답성 나노복합재료의 열안정성이 열응답성 고분자에 비하여 우수하였음을 보였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.18-18
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• 2003

Natural clays are composed of oxide layers whose thickness is about 1nm and cations existing between the layers. A number of these layers makes primary particles with a height of about 8∼10nm and these primary particles make aggregates with a size of about 0.1∼10$\mu\textrm{m}$. When layered silicate was made to be organophilic, by exchanging the interlayer cations with organic cationic molecules, the matrix polymer can penetrate between the layers to give a nanocomposite, where 1nm-scal clay layers exist separately in a continuous polymer matrix. These nanostructured hybrid organic-inorganic composites have attracted the great interest of researchers over the last 10 years. They exhibit improved performance properties compared with conventional composites, because their unique phase morphology by layer intercalation or exfoliation maximizes interfacial contact between the organic and inorganic phases and enhances interfacial properties. Since the advent of nylon-6/montmorillonite nanocomposite developed by Toyota Motor Co., the studies on layered silicate-polymer nanocomposites have been successfully extended to other polymer systems. They greatly improved the thermal, mechanical, barrier, and even the flame-retardant properties of the polymers.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.95-96
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• 2006

Surface modification of clay minerals has become increasingly important for improving the practical applications of clays such as polymeric nanocomposites. We used the copolymer as modifiers having phenyl components, and successfully developed a route for the preparation of amine functionalized polymer based on oligostyrene and its block copolymers. The oligo(St-co-VBC)s with controlled molecular weight were synthesized via nitroxide mediated polymerization method. We also successfully prepared organophilic layered silicates whose surface is covered with styrenic copolymers. Through the analysis of chemical structure and morphology, we concluded that copolymers were very effective organic modifiers to change the surface characteristics of layered silicates.