• 제목/요약/키워드: Carbon-carbon coupling

검색결과 168건 처리시간 0.026초

흑연의 실란커플링에 의한 수지함침 (The Resin Impregnation with Silane Coupling on Graphite)

  • 조광연;김경자;정윤중
    • 한국세라믹학회지
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    • 제40권10호
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    • pp.1021-1026
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    • 2003
  • 탄소재의 수지함침은 탄소재 표면 상태에 영향을 받는다. Coupling처리에 의한 탄소재 표면처리는 수지와의 호환성과 젖음성을 개선시켜 함침효율과 물성을 향상시킨다. 본 연구에서는 표면개질을 위해 탄소재를 실란 coupling 처리하였다. FT-IR 관찰결과 실라놀은 탄소재 표면에 단층으로 코팅되었음을 확인하였다. 탄소재의 coupling 처리는 함침효율을 향상시켜 기공율, 기계적 강도, 밀도, 마찰거동이 개선되었다.

팔라듐 촉매를 이용한 퀴놀론핵과 Heteroaryl Stannes의 결합 - C-7 heteroaryl 쿼놀론 유도체의 합성 - (Palladium-Catalyzed Coupling between Quinolone Moieties and Heteroaryl Stannes - Synthesis of C-7 heteroaryl Quinolone Derivatives -)

  • 남상훈;함원훈;김기수;임태균;양재권
    • 약학회지
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    • 제37권6호
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    • pp.615-620
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    • 1993
  • The cross-coupling reaction of organo tin reagents with a variety of organic halides, catalyzed by palladium, provides a novel method for generating a carbon-carbon bond. We used this method for the antibacterial agents, and synthesis of new quinolone derivatives which have carbon-carbon bond at C-7 position of general quinolone moieties. Aryl tin, quinolone moieties, and palladium catalyst were refluxed in DMF to afford new quinolone derivatives. This palladium catalyzed coupling reactions have capacity for further synthetic elaboration.

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Influence of a silane coupling agent on the optoelectrical properties of carbon nanotube/binder hybrid thin films

  • Han, Joong-Tark;Woo, Jong-Seok;Jeong, Hee-Jin;Jeong, Seung-Yol;Lee, Geon-Woong
    • Carbon letters
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    • 제12권2호
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    • pp.90-94
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    • 2011
  • We present the effect of a coupling agent on the optoelectrical properties of few-walled carbon nanotube (FWCNT)/epoxy resin hybrid films fabricated on glass substrates. The FWCNT/epoxy resin mixture solution was successfully prepared by the direct mixing of a $HNO_3$-treated FWCNT solution and epoxy resin. FWCNT/binder hybrid films containing different amounts of the coupling agent were then fabricated on UV-ozone-treated glass substrates. To determine the critical binder content ($X_c$), the effects of varying the binder content in the FWCNT/silane hybrid films on their optoelectrical properties were investigated. In this system, the $X_c$ value was approximately 75 wt%. It was found that above $X_c$, the coupling agent effectively decreased the sheet resistance of the films. From microscopy images, it was observed that by adding the coupling agent, more uniform FWCNT/binder films were formed.

Fluoro-quinolone Carboxylic Acid 유도체로부터 탄소-불소 및 수소-불소간 Coupling Consstants의 조사 (Survey of Carbon- and Proton-Fluorine Coupling Constants in Fluoro-quinolone Carboxylic Acid Derivatives)

  • 고동수;이인원;임융호
    • Applied Biological Chemistry
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    • 제41권7호
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    • pp.550-555
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    • 1998
  • Fluoro-quinolone carboxilic acid 유도체에서, 탄소-불소간 one bond coupling constants는 위치와 무관하게 249 Hz에서 257 Hz 사이의 값을 갖는데, geminal 및 vicinal coupling constants는 위치에 따라 그 값의 차이가 많이 생긴다. 즉, seminal coupling constants는 6 Hz에서 23 Hz의 값을 보이고 vicinal coupling constants는 1.9 Hz에서 7 Hz의 값을 보인다. 또한 수소-불소간 three bond coupling constants는 9 Hz에서 10.3 Hz의 값을 보이고, four bond coupling constants는 6 Hz에서 8.3 Hz의 값을 보인다.

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Palladium-Catalyzed Coupling between Quinolone Moieties and Heteroacyl Stannes - Synthesis of C-7 Heteroacyl Quinolone Derivatives

  • 함원훈;양재권;임태균
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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    • pp.221-221
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    • 1994
  • The cross-coupling reaction of organo tin reagents with a variety of organic halides, catalyzed by palladium, provides a novel method for generating a carbon-carbon bond. We use this method for antibacterial agents, and synthesis of new quinolone derivatives which have carbon-carbon bond at C-7 position of general quinolone moieties. Aryl tin, quinolone moieties, and palladium catalyst were refluxed in DMF to afford new quinolone derivatives. This palladium catalyzed coupling reactions have capacity for further synthetic elaboration.

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Influence of Silane Coupling Agent on Properties of Filled Styrene-Butadiene Rubber Compounds

  • Park, Sung-Seen
    • Macromolecular Research
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    • 제8권6호
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    • pp.285-291
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    • 2000
  • Influence of silane coupling agent, bis-(3-(triethoxisilyl)-propyl)-tetrassulfide, on cure characteristics and bound rubber content of filled styrene-butadiene rubber (SBR) compounds and on physical properties of the vulcanizates was studied. Carbon black-filled and silica-filled compounds were compared. Content of the bound rubber increased with increased content of the silane coupling agent and this trend was shown more clearly in the silica-filled compounds. Optimum cure time of the carbon black-filled compound increased with increase of the silane content, while that of the silica-filled one decreased. Cure rate of the carbon black-filled compound became slower as the silane content increased while that of the silica-filled one became faster. By increasing the silane content, the minimum torque decreased and the delta torque increased. Physical properties of the silica-filled vulcanizate were found to be improved by adding the silane coupling agent. However, for the carbon black-filled vulcanizates, the tensile strength and tear resistance decreased with increase of the silane content. The differences between the carbon black-filled and silica-filled compounds were explained by difference in the reactivities of the fillers with the silane.

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Effect of fiber-matrix adhesion on the fracture behavior of a carbon fiber reinforced thermoplastic-modified epoxy matrix

  • Carrillo-Escalante, H.J.;Alvarez-Castillo, A.;Valadez-Gonzalez, A.;Herrera-Franco, P. J.
    • Carbon letters
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    • 제19권
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    • pp.47-56
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    • 2016
  • In this study, the fracture behavior of a thermoplastic-modified epoxy resin reinforced with continuous carbon fibers for two levels of fiber-matrix adhesion was performed. A carbon fiber with commercial sizing was used and also treated with a known silane, (3-glycidoxy propyl trimethoxysilane) coupling agent. Toughness was determined using the double cantilever test, together with surface analysis after failure using scanning electron microscope. The presence of polysulfone particles improved the fracture behavior of the composite, but fiber-matrix adhesion seemed to play a very important role in the performance of the composite material. There appeared to be a synergy between the matrix modifier and the fiber-matrix adhesion coupling agent.