• 제목/요약/키워드: polymerization ability

검색결과 64건 처리시간 0.023초

Results Of Mathematical Modeling Of Organizational And Technological Solutions Of Effective Use Of Available Resource Of Modern Roofs

  • Arutiunian, Iryna;Mishuk, Katerina;Dankevych, Natalia;Yukhymenko, Artem;Anin, Victor;Poltavets, Maryna;Sharapova, Tetiana
    • International Journal of Computer Science & Network Security
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    • 제21권1호
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    • pp.49-54
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    • 2021
  • Relative to the outer surface of the mastic coating, the reliability of the available waterproofing resource is determined by the ability to stabilize the structural characteristics in difficult climatic conditions. Organic components of mastic as a result of solar radiation, elevated temperatures and their alternating change, atmospheric oxidants, especially in industrial areas, have a tendency to self-polymerization and loss of low molecular weight components. This is the gradual loss of deformability and the transition to brittleness with its tendency to crack as the reasons for the gradual transition from normal to emergency operating condition.The presented mechanism of functioning of the coating surface indicates the expediency of increasing its components, able to stabilize the structure and prevent changes in deformability.Durability, hydrophobicity, water displacement, water absorption are accepted as estimating indicators. The main dependences of the influence of the lost additional components of mastic on the operational properties of the formed coating characterize the ability to provide successful resistance to environmental influences and longer stability. As a result, mastic acquires additional service life.

A Study of Characteristics Variation of Thermally Expandable Microspheres in Post-polymerization Treatment by Various Initiators

  • You, Hae Na;Kim, Ji Hoo;Kim, Myeong Woo;Kim, Keon Il;Park, Hyun Duk
    • Elastomers and Composites
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    • 제52권3호
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    • pp.211-215
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    • 2017
  • Thermally expandable microspheres were used as post-treatment initiators of potassium persulfate, sodium bisulfite, and sodium sulfide in order to improve the foaming ability and whiteness when foaming a mixture of thermally expandable microsphers and poly(vinyl chloride). Potassium persulfate showed no significant influence on the foaming behavior, foam expansion, whiteness, and yellowing, whereas in the case of using sodium bisulfite. In particular, sodium bisulfite demonstrated the best efficiency with 2 wt% treatment. The thermally expandable microspheres prepared herein can provide excellent foamability and whiteness, and are expected to be applicable in various fields such as general coating and wallpaper.

Synthesis and Optical Properties of Poly(hydroxyphenylbenzoxazole): A Colorimetric and Fluorescent Sensor for Ionic Species

  • Lee, Jin-Koo;Kim, Tae-Hyun;Kim, Young-shin;Gang Li;Park, Won-Ho;Lee, Taek-Seung
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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    • pp.23-24
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    • 2003
  • We synthesized a poly[2-(2'-hydroxyphenyl) benzoxazole] under the two step procedures of Suzuki coupling polymerization with corresponding monomers followed by the deprotection of benzyl group. The polymer in DMF solution is applicable to colorimetric sensing fluoride anion, which shows a color change from colorless to yellow. High sensitivity to fluoride anion compared to other anions such as phosphate, chloride, and sulfate is ascribed to the high coordination ability of the 2-(2'-hydroxy phenyl)benzoxazole moiety in the polymer chain. Emission shift by metal cations, which can be applied to fluorescent sensing w as also observed in the polymer solution.

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Molecularly Imprinted Monolithic Stationary Phases for Liquid Chromatographic Separation of Tryptophan and N-CBZ-Phenylalanine Enantiomers

  • Yan, Hong-Yuan;Row, Kyung-Ho
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제11권4호
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    • pp.357-363
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    • 2006
  • Monolithic molecularly imprinted columns were designed and prepared by an in-situ thermal-initiated copolymerization technique for rapid separation of tryptophan and N- CBZ-phenylalanine enantiomers. The influence of polymerization conditions and separation conditions on the specific molecular recognition ability for enantiomers and diastereomers was investigated. The specious molecular recognition was found to be dependent on the stereo structures and the arrangement of functional groups of the imprinted molecule and the cavities in the molecularly imprinted polymer (MIP). Moreover, hydrogen bonding interactions and hydrophobic interactions played an important role in the retention and separation. Compared to conventional MIP preparation procedures, the present method is very simple, and its macroporous structure has excellent separation properties.

Polystyrene Microgel with Maltohexaose. Synthesis and Potential Application for Fullerene-Coating on Hydrophilic Surface

  • Narumi, Atsushi
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.318-318
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    • 2006
  • 4-Vinylbenzyl maltohexaoside peracetate, 1, was copolymerized with divinylbenzene using the initiator for nitroxide-mediated living radical polymerization, 2, to afford the polystyrene microgel with acetyl maltohexaose, 3. The deacetylation of 3 was achieved by treatment with sodium methoxide in dry 1,4-dioxane to produce the polystyrene microgel with maltohexaose, 4. A good coating property of the polystyrene microgel was combined with an excellent hydrophilic property derived from maltohexaose. In addition, 4 showed the ability to solubilize fullerene in aqueous solution. Therefore, 4 has a potential application as a special coating using functional but incompatible compounds such as fullerene on the surface of various hydrophilic materials.

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Synthesis and Characterization of Poly(p-phenylenevinylene) Derivatives Containing Alkylphenylsilyl Pendant Group

  • Joo, Mun-Kyu;Jin, Sung-Ho;Lee, Kwang-Hee;Gal, Yeong-Soon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.970-973
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    • 2003
  • A new class of soluble PPV derivatives containing dimethyldodecylsilylphenyl unit as a pendant was synthesized by Gilch polymerization method. The resulting electroluminescent (EL) polymers showed good solubility, good film-forming ability onto the ITO substrate, and exhibited an amorphous morphology due to dimethyldodecylsilylphenyl branched group linked to the polymer backbone. The weight average molecular weights and polydispersities of the present EL polymers were in the range of 8.0-80.0 x $10^{4}$ and 2.67-7.80, respectively. The resulting EL polymers revealed a high thermal stability of up to $355-410^{\circ}C$. Their glass transition temperatures were in the range of $104-251^{\circ}C$. The emission colors could be tuned from green to orange-red colors by changing the MEH-PPV contents in copolymer systems. The turn-on voltages of the EL polymers were in the range of 1.8-4.0 V.

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PEDOT Polymer Film Based Counter Electrodes for Pt-free Dye-Sensitized Solar Cells

  • Kwon, Jeong;Park, Jong Hyeok
    • Journal of Electrochemical Science and Technology
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    • 제4권3호
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    • pp.89-92
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    • 2013
  • Poly (3,4-ethylenedioxythiophene) (PEDOT) polymers with different electric conductivities were synthesized directly on a FTO substrate via a chemical polymerization method and applied as a platinum (Pt)-free counter electrode for dye-sensitized solar cells (DSSCs). The catalytic properties of the PEDOT as a function of electrical conductivity were studied using cyclic voltammograms, J-V measurements and impedance spectroscopy. The PEDOT counter electrode with around 340 S/cm conductivity exhibited the best performance as a counter electrode for tri-iodide reduction. The ability to modulate catalytic activity of PEDOT with changes in conductivity shows one of promising routes for developing new counter electrode of Pt-free DSSCs.

Catechol-mediated Functional Coatings of Polymer and Inorganic Nanostructures

  • 김지선;박재윤;손호연;이해신;남윤성
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2012년도 추계총회 및 학술대회 논문집
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    • pp.66-67
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    • 2012
  • As polymer coatings of nano-structured surface become significant to obtain functionalized materials, catechol derived from a mussel protein has attracted increasing attention for its universal adhesiveness. In addition to the unique adhesion property, its reducing ability of metal ions during oxidative polymerization to polydopamine (pD) widely expands the application of catechol molecules in the field of surface modification. In this study, we present the catechol conjugated smart polymer coatings for regulating surface properties such as wettability and anti-fouling effects. In additino, the in situ silver coating of electrospun polymer nanofibers using a silver-catechol redox reaction is presented as a simple method to produce metal nanostructures.

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Preparation of 3,4-Ethylenedioxythiophene (EDOT) and N-4-butylphenyl-N,N-diphenylamine (BTPA) Copolymer Having Hole Transport Ability

  • Sim, Jae-Ho;Sato, Hisaya
    • Macromolecular Research
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    • 제17권9호
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    • pp.714-717
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    • 2009
  • Hole transport copolymers consisting of 3,4-ethylenedioxythiophene (EDOT) and N-4-butylphenyl-N,N-diphenylamine (BTPA) were synthesized by oxidative coupling reaction using $FeCl_3$ as an oxidant. These copolymers showed good solubility and their thin films showed sufficient morphological stability. The copolymers showed an absorption maximum around 320 nm. Copolymers had an oxidation peak at approximately $1.03{\sim}1.14V$ versus the Ag/AgCl electrode. The hole mobility increased with increasing portion of the EDOT unit. The hole mobility of the copolymer containing 57% of the EDOT unit showed the highest mobility of $3{\times}10^{-5}cm^2/V{\cdot}s$.

Versatile Strategies for Fabricating Polymer Nanomaterials with Controlled Size and Morphology

  • Yoon, Hyeon-Seok;Choi, Moon-Jung;Lee, Kyung-Jin;Jang, Jyong-Sik
    • Macromolecular Research
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    • 제16권2호
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    • pp.85-102
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    • 2008
  • The development of reliable synthetic routes to polymer nanomaterials with well-defined size and morphology is a critical research topic in contemporary materials science. The ability to generate nanometer-sized polymer materials can offer unprecedented, interesting insights into the physical and chemical properties of the corresponding materials. In addition, control over shape and geometry of polymer nanoparticles affords versatile polymer nanostructures, encompassing nanospheres, core-shell nanoparticles, hollow nanoparticles, nanorods/fibers, nanotubes, and nanoporous materials. This review summarizes a diverse range of synthetic methods (broadly, hard template synthesis, soft template synthesis, and template-free synthesis) for fabricating polymer nanomaterials. The basic concepts and significant issues with respect to the synthetic strategies and tools are briefly introduced, and the examples of some of the outstanding research are highlighted. Our aim is to present a comprehensive review of research activities that concentrate on fabrication of various kinds of polymer nanoparticles.