• 제목/요약/키워드: in-situ polymerization

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In-situ Synthesis of Polyamide-6/POSS Nanocomposites

  • Ramasundaram Subramaniya Pillai;Kim Kap-Jin
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.303-303
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    • 2006
  • In-situ ring opening polymerization of ${\varepsilon}-caprolactum$ was carried out in the presence of aminoethylaminopropylisobutyl POSS and stoichiometric amount of adipic acid. The covalent bond formation of POSS on the polyamide was confirmed by the appearance of FT-IR peak at $1123\;cm^{-1}$ that corresponds to the Si-O stretching of POSS structures. Gradual decrease in melting endotherm peak was observed on loading POSS in PA6/POSS nanocomposites. Sharp increase in intrinsic viscosity was observed upto 2.5 wt % loading POSS in the polyamide 6 nanocomposites. These nanocomposites were further characterized using nuclear magnetic resonance, melt viscosity and X-ray diffraction.

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in situ중합을 통한 나일론 6-PEG 랜덤공중합체/점토 나노복합체의 합성 및 물성 (Synthesis and Properties of Nylon 6/PEG Random Block Copolymer/Clay Nanocomposite via in situ Polymerization)

  • Angelica S. Lopez;Pio Sifuentes;Kim, Kap-Jin
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2003년도 봄 학술발표회 논문집
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    • pp.72-74
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    • 2003
  • There has been extensive interest in the development of new nanocomposites. One kind of these systems is the hybrid based on organic polymers and inorganic minerals consisting of layered silicates. Some properties like stiffness, strength, barrier properties, thermal, and oxidative stability can be improved by the presence of the filler in the polymeric matrix[1]. It is reported that, in the nylon 6/clay nanocomposites, the modulus is increased, but impact strength and elongation at break are drastically decreased. (omitted)

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In-Situ Cross-linked Polymer Electrolyte Membranes from Thermally Reactive Oligomers for Direct Methanol Fuel Cells

  • Kim, Hae-Kyoung;Lee, Won-Mok;Park, Sam-Dae;Chang, Yoon-Ju;Jung, Jin-Chul;Chang, H.
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.271-271
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    • 2006
  • The present article describes a novel method of preparing the sulfonated polysulfone-based PEMs for DMFC, which are excellent in film quality, proton conductivity, methanol impermeability and mechanical properties. No depression in film quality or difficulty in film preparation is observed, even though sulfonated group of the PEMs are kept as high as 70 mol %. Allyl-terminated cooligo-PESs containing the organic sulfonate groups were solvent-cast into films and then thermally treated for cross-linking. Cross-linked sulfonated polysulfone-based PEMs gave unprecedented reduction of methanol cross-over and high ionic conductivity through in-situ thermal polymerization and cross-linking of telechelic sulfonated sulfone oligomers during a membrane preparation.

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유기 절연층에 따른 유기 TFT 특성 연구 (Study on the Characteristics of Organic TFT Using Organic Insulating Layer Efficiency)

  • 표상우;이민우;손병천;김영관
    • 한국응용과학기술학회지
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    • 제19권4호
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    • pp.335-338
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    • 2002
  • A new process for polymeric gate insulator in field-effect transistors was proposed. Fourier transform infrared absorption spectra were measured in order to identify ODPA-ODA polyimide. Its breakdown field and electrical conductivity were measured. All-organic thin-film transistors with a stacked-inverted top-contact structure were fabricated to demonstrate that thermally evaporated polyimide films could be used as a gate insulator. As a result, the transistor performances with evaporated polyimide was similar with spin-coated polyimide. It seems that the mass-productive in-situ solution-free processes for all-organic thin-film transistors are possible by using the proposed method without vacuum breaking.

Pervaporation of aqueous organic mixture through in situ complex membranes based on polycrylonitrile

  • Lee, Young-Moo;Oh, Boo-Keun
    • 한국막학회:학술대회논문집
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    • 한국막학회 1995년도 제3회 심포지움 (분리막 연구의 최신동향)
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    • pp.39-55
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    • 1995
  • Modified polycrylonitrile(PAN) membranes were prepared by emulsion or emulsifier-free emulsion polymerization technique. Separation capacity was determined at several operating temperatures(25, 40, 55 and 70 $^{\circ}$C) to dehydrate 56wt% pyridine aqueous solution through modified PAN membranes having different functional groups. All these PAN-based membranes were selective toward water to different degrees depending on the nature of functional groups present in the membranes. Pervaporation characteristics of PAN-based membranes are so different and classified into three categories depending on the type of the functional groups in PAN copolymers. Among PAN-based membranes, the in-situ complex membranes show the best separation capacity over the operating temperatures.

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Preparation of Microcapsules Containing Fragrant Oil and Its Application to Textile Finishing

  • Hwang, Jun-Seok;Kim, Jin-Nam;Wee, Young-Jung;Ryu, Hwa-Won;Yun, Jong-Sun;Jang, Hong-Gi;Kim, Sun-Ho
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2005년도 생물공학의 동향(XVII)
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    • pp.860-863
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    • 2005
  • The microcapsules containing fragrant oil as functional material were prepared by in-situ polymerization with prepolymer that was made from melamine-formaldehyde (MF) as wall material of microcapsules. The effects of polymerization variables, such as the nature and concentration of surfactants, stirring rate, and stirring time, on the size and distribution of the particles were investigated. Fourier transform-infrared spectroscopy (FT-IR), thermal analysis, particle size analysis, scanning electron microscopy (SEM) observation were used to investigate the characteristics of microcapsules. Through the FT-IR and SEM analysis, we found that the prepared microcapsules were containing fragrant oil and the shape of particle was spherical. The nature and concentration of surfactants, stirring rate, and stirring time had profound effects on the particle size and particle size distribution.

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피톤치드오일을 함유한 우레아-포름알데히드 마이크로캡슐의 제조와 성질 (Preparation and Properties of Urea-Formaldehyde Microcapsules Containing Phytoncide Oil)

  • 황진철;박윤정;김혜인;박수민
    • 한국염색가공학회:학술대회논문집
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    • 한국염색가공학회 2008년도 제38차 학술발표대회
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    • pp.111-113
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    • 2008
  • In this study, for natural leather use, the phytoncide oil of antibacterial materials was encapsulated in several micro-diameter shell which slowly releases from the leather treated with antibacterial microcapsules. The microcapsule was synthesized by in-situ polymerization of urea and formaldehyde. The effects of surfactants on the average particle size and distributions, morphologies and antibiosis were investigated to design microcapsule.

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연꽃잎을 모사한 초소수성 표면 제작 (Fabrication of the Superhydrophobic Surface Inspired from Lotus-Effect)

  • 정대환;임현의;노정현;김완두
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.409-414
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    • 2007
  • Wettability of solid surfaces with liquids is governed by the chemical properties and the microstructure of the surfaces. We report on the preparation of liquid-repellent surfaces using surface-attached monolayers of perfluorinated polymer molecules on porous silica substrates. A covalent attachment of the polymer molecules to the substrate is achieved by generation of the polymer chains through starting a surface-initiated radical-chain polymerization of a fluorinated monomer. To this, self-assembled monolayers of azo initiators are attached to silica substrates, which are used to kick off the polymerization reaction in situ. The growth of the fluorinated polymer films and the characterization of the obtained surfaces by surface plasmon spectroscopy, XPS, and contact angle measurements is described. It is shown that perfluorinated polymer films can be grown with controlled thicknesses on flat and even on porous silica surfaces, essentially without changing the surface roughness. The combination of the low surface energy coating and the surface porosity allows generation of materials which are both water and oil repellent.

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Templated Formation of Silver Nanoparticles Using Amphiphilic Poly(epichlorohydrine-g-styrene) Film

  • Park, Jung-Tae;Koh, Joo-Hwan;Seo, Jin-Ah;Roh, Dong-Kyu;Kim, Jong-Hak
    • Macromolecular Research
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    • 제17권5호
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    • pp.301-306
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    • 2009
  • This work has demonstrated that a novel amphiphilic poly(epichlorohydrine)-graft-polystyrene (PECH-g-PS) copolymer at 34:66 wt% was synthesized via atom transfer radical polymerization (ATRP) of styrene using PECH as a macroinitiator. The structure of the graft copolymer was characterized by nuclear magnetic resonance ($^1H$ NMR) and FTIR spectroscopy, demonstrating that the "grafting from" method using ATRP was successful. The self-assembled graft copolymer was used as a template film for the in-situ growth of silver nanoparticles from $AgCF_3SO_3$ precursor under UV irradiation. The in situ formation of silver nanoparticles with 6-8 nm in average size in the solid state template film was confirmed by transmission electron microscopy (TEM), UV-visible spectroscopy and wide angle X-ray scattering (WAXS). Differential scanning calorimetry (DSC) also displayed the selective incorporation and the in situ formation of silver nanoparticles within the hydrophilic PECH domains, probably due to stronger interaction of the silvers with the ether oxygens of PECH backbone than that with hydrophobic PS side chains.