• 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.

• Fibers and Polymers
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• 제5권1호
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• pp.59-67
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• 2004

The development of high tenacity, high modulus monofilaments from Polypropylene/Clay nanocomposite has been investigated. Pure sodium montmorillonite nanoclay was modified using hexadecyl trimethyl ammonium bromide (HTAB) via an ion exchange reaction. Pure and modified clay were characterized through X-ray diffraction, FTIR and TGA. The modified clay was melt blended with polypropylene (PP) in presence of a swelling agent. Composite filaments from PP/Clay nanocomposite were prepared at different weight percentages of nanoclay and the spinning and drawing conditions were optimized. The filaments were characterized for their mechanical, morphological and thermal properties. The composite PP filaments with modified clay showed improved tensile strength, modulus and reduced elongation at break. The composite filaments with unmodified clay did not show any improvement in tensile strength but the modulus improved. The sharp and narrow X-ray diffraction peaks of PP/nanoclay composite filaments indicate increase in crystallinity in presence of modified clay at small loadings (0.5 %). The improved thermal stability was observed in filaments with modified as well as unmodified clays.

• Macromolecular Research
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• 제14권3호
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• pp.312-317
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• 2006

In the preparation of a polyacrylonitrile (PAN)/sodium montmorillonite (Na-MMT) nanocomposite via an in-situ polymerization method, macroazoinitiator (MAI) was intercalated in the gallery of Na-MMT to enhance the delamination of silicate layers by intergallery polymerization. The exfoliated fine dispersion observed by X-ray diffraction pattern and transmission electron microscopy, the enhanced tensile storage modulus and the thermal decomposition temperature showed that the intercalated MAI was effective in inducing intergallery polymerization and that a poly(ethylene glycol) block linked to a PAN block improved the dispersion of hydrophilic Na-MMT in the polymer matrix.

• 폴리머
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• 제32권4호
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• pp.347-352
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• 2008

직접 중합법으로 내충격성 폴리스티렌(HIPS)과 유기화 점토로 구성된 나노복합재료를 합성하여 점토 첨가에 따른 물성을 조사하였다. 반응성 작용기를 갖는 유기화 점토인 vinylbenzyltrimethyl clay(VBC)와 octadecylvinylbenzyldimethyl clay(ODVC)를 sodium montmorillonite와 계면활성제인 vinylbenzyltrimethyl ammonium chloride(VBTMAC)와 octadecylyinylbenzdimethyl ammonium bromide(ODVBDAB)의 이온교환으로 각각 제조하였고 상용화된 유기화 점토인 $Cloisite^{(R)}$ 10A(C10A)를 비교를 위해 사용하였다. ODVD로 제조한 나노복합재료의 경우 X-선 회절(XRD) 피크가 사라진 것으로 보아 실리케이트 층이 박리된 것을 알 수 있었고, C10A로 제조한 나노복합재료의 경우 XRD 피크의 각도가 작은 쪽으로 이동하는 것으로 보아 실리케이트 층에 고분자 사슬이 층간 삽입된 것을 알 수 있었다. 저장탄성률과 복소점도로 나타낸 유변물성은 유기화 점토의 함량이 증가할수록 증가하였다.

• 한국응용과학기술학회지
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• 제20권3호
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• pp.243-250
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• 2003

Poly(methyl methacrylate)/clay nanocomposite particles with particle size of 275${\sim}$292 nm range were successfully prepared using emulsion polymerization. The content of montmorillonite based on the methyl methacrylate monomer was chosen as 30 wt.%. 2,2-azobis(isobuthylamidine hydrochloride) and n-dodecyltrimethylammonium chloride were used as an initiator and a surfactant in cationic emulsion system. Potassium persulfate and sodium lauryl sulfate were used as an initiator and a surfactant in anionic emulsion system. The evidence of intercalated /exfoliated structure of montmorillonite in the nanocomposite prepared in our experiment was confirmed by wide angle x-ray diffraction patterns of $d_{001}$ plane. Thermal behavior of nanocomposite was traced using DSC and TGA. It was found that the nanocomposite particle prepared by cationic emulsion system showed intercalated structured. We also found that the nanocomposite particle obtained from anionic emulsion system resulted in the fully exfoliated structure.

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1669-1674
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• 2012

A novel superabsorbent composite was prepared by intercalation polymerization of acrylic acid (AA) and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) in the presence of montmorillonite (MMT), using ammonium persulfate (APS) as an initiator and $N,N'$-methylenebisacrylamide (MBA) as a cross linker. The superabsorbent composite was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Maximum absorbency of the composite in distilled water and 0.9% sodium chloride solution was 722 and 108 g/g, respectively. The composite was used for removal of heavy metal ions from aqueous solutions. Maximum amount of adsorption for $Ni^{2+}$, $Cu^{2+}$ and $Pb^{2+}$ was 211.0, 159.6 and 1646.0 mg/g, respectively, and the adsorption was in accordance with both Langmuir and Freundlich model. The composite could be regenerated and reused in wastewater treatment.

• 폴리머
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• 제26권3호
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• pp.375-380
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• 2002

합성한 polyamic acid의 말단기인 anhydride기와 반응시키기 위하여 나트륨 몬모릴로나이트에 diamine (p-phenylenediamine, m-phenylenediamine, and n-hexamethylenediamine)을 삽입시켰다. 그리고 4,4'-oxydianilline : 1,2,4,5-benzene tetracarboxylic dianhydride의 몰비를 1.50 : 1.53으로 하여 말단기가 anhydride된 polyamic acid를 합성하였다. 이렇게 치환된 몬모릴로나이트를 말단기가 anhydride된 polyamic acid와 N-methyl-2-pyrrolidone용액에서 반응시켰다 (polyamic acid/clay nanocomposite) 이것을 열이미드화하여 polyimide/clay 나노복합재료를 제조하였다. XRD와 TEM으로 관찰한 결과 실리케이트 층이 단일층으로 폴리이미드 매트릭스에 잘 분산되어 있는 박리형 폴리이미드 나노복합재료가 제조되었음을 알 수 있었다. 이들의 기계적 특성을 관찰한 결과 박리형 폴리이미드 나노복합재료의 경우가 순수한 폴리이미드와 삽입형 폴리이미드 나노복합재료의 경우보다 우수함을 알 수 있었다.

• 자원환경지질
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• 제16권3호
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• pp.149-161
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• 1983

경상도(慶尙道) 지역(地域)의 삼기층중(三紀層中)에 배태(胚胎)되어진 산성백토(酸性白土)는 주(主)로 Ca-몽모리로나이트로 구성되며 이의 조성비(組成比)는 95%까지에 이른다. 이에 수반되는 광물(鑛物)은 크리스토발라이트, 석영(石英), 장석(長石), 삼정석광물(三井石鑛物) 및 비결정질(非結晶質)이 있다. 시차열분석(示差熱分析), 적외선 및 전자현미경에 의한 이들의 기본적인 특성(特性)을 기재하였고 물리적성질(物理的性質)을 섭성한계(涉性限界) 및 양이온교환능을 측정기재하였다. 이들 자원(資源)의 이용가능한 용도범위를 고찰하였다.

• 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.

• 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.