• 제목/요약/키워드: High Polymer

검색결과 3,738건 처리시간 0.03초

High Performance Phenoxytitanium-Based Catalysts for Olefin Polymerization

  • Miyatake, Tatsuya
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.159-160
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    • 2006
  • We developed novel catalyst, PHENICS composed of the combination of a cyclopentadienyl group to perform a high catalytic activity and a bulky phenoxy group, which performs the production of high molecular weight polyolefin. The polymerization activity of PHENICS at high temperature is higher than well-known CGC catalyst. PHENICS showed the excellent ability of comonomer incorporation into polymer chain. The obtained copolymer had a high molecular weight. The PHENICS catalyst is also active to the copolymerization of ethylene and several vinyl comonomers such as styrene, norbornen, and conjugated dienes. We will discuss new cocatalysts for PHENICS to improve activity and the ability of molecular weight control.

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철근보강 폴리마 콘크리트보의 변형특성 (Deformation Characteristics of Reinforced Polymer Concrete Beams)

  • 연규석
    • 한국농공학회지
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    • 제30권1호
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    • pp.63-72
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    • 1988
  • The primary objective of the study was to find the deformation characteristics of reinforced polymer concrete beams. A test program was carried out to compare the behavior in deformation of polyester and MMA concrete beams with cement concrete beams but with varying ratios of tensile reinforcement. From the results the following conclusions can be made. 1.The various strengths of polymer concrete ware very high compared to the strengths for cement concrete. Also, compared to conventional concrete beams, flexural strength of reinforced polymer concrete beams was distinctly higher for the same section and steel ratios. 2.The polymer concrete beams exhibit large deflections accompanied by relatively high strengths as compared to cement concrete beams. 3.The average ultimate strain at the extreme compression fiber of polymer concrete beams was 0.01 1 cm / cm, and this value was about three to four times as large as that of cement concrete beams, 4.The polymer concrete beams developed more cracks which were more wide crack distribution spacing than the cement concrete beams, and the beams failed in a more ductile manner. 5.The reinforcing steel ratio has a significant effect on the beam strength, load-deflection response, stress-strain curve, and crack pattern of polymer concrete beams.

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Study on the Cycling Performances of Lithium-Ion Polymer Cells Containing Polymerizable Additives

  • Kim, Dong-Won
    • Bulletin of the Korean Chemical Society
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    • 제30권2호
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    • pp.319-322
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    • 2009
  • Gel polymer electrolytes were prepared by immersing a porous poly(vinylidene fluoride-co-hexafluoropropylene) membrane in an electrolyte solution containing small amounts of polymerizable additive (3,4-ethylenedioxythiophene, thiophene, biphenyl). The organic additives were electrochemically oxidized to form conductive polymer films on the electrode at high potential. With the gel polymer electrolytes containing different organic additive, lithium-ion polymer cells composed of carbon anode and LiCo$O_2$ cathode were assembled and their cycling performances were evaluated. Adding small amounts of thiophene or 3,4-ethylenedioxythiophene to the gel polymer electrolyte was found to reduce the charge transfer resistance in the cell and it thus exhibited less capacity fading and better high rate performance.

Viewing Angle Switching using Hybrid Aligned Nematic Liquid Crystal Display Driven by a Fringe-Field

  • Chin, Mi-Hyung;Jeong, Eun;Lim, Young-Jin;Kim, Jin-Ho;Srivastava, Anoop Kumar;Lee, Seung-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1386-1389
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    • 2008
  • Conventional viewing angle switching electrode requires pixel division and additional liquid crystal panel. Hence the conventional viewing angle switching has low aperture ratio and high thickness. In this paper we proposed new viewing angle switching using hybrid aligned nematic mode by fringe-field electrode field (named HAN-FFS) with single liquid crystal panel. The fringe-field switching electrode is located at the bottom, and the additional common electrode is located at the top of the cell to control viewing angle. The proposed device is free from additional liquid crystal panel and pixel division. Consequently, the suggested structure has not only high aperture ratio but also show an excellent potential for viewing angle switching.

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코아 가교 양친성 고분자 나노입자를 이용한 고함량 유용 약물 담지 고분자 나노입자 제조 (Preparation of Valuable Compounds Encapsulated Polymer Nanoparticles with High Payload Using Core-crosslinked Amphiphilic Polymer Nanoparticles)

  • 김나혜;김주영
    • 공업화학
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    • 제27권1호
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    • pp.26-34
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    • 2016
  • 본 연구에서는 반응성 비닐기를 가지고 있는 반응성 양친성 고분자 전구체(Reactive Amphiphilic Reactive Polymer Precursor) (RARP)를 이용하여 제조된 소수성 세그먼트들이 가교된 코아 가교 양친성 고분자(Core-crosslinked Amphiphilic Polymer) (CCAP) 나노입자와 나노침전법을 사용하여서 소수성 유용물질을 고함량으로 담지할 수 있는 새로운 공정을 제안하였다. 극성이 각기 다른 유기용매(에탄올, 아세톤, 테트라하이드로퓨란(THF))들과 소수성 세그먼트 분자량이 다른 CCAP를 사용하여서, 모델 유용 약물인 ${\alpha}$-tocopherol의 담지 효율, 담지량 및 약물 담지 나노입자의 크기와 안정성 변화를 조사하였다. 소수성 세그먼트 분자량이 큰 CCAP와 소수성 용매인 THF를 용매로 사용한 경우에 가장 높은 유용 약물 담지량, 담지 효율을 나타내는 안정한 나노입자가 형성이 되었다. 즉 CCAP 나노입자들의 물리적 화학적으로 견고한 나노 구조로 인해서 33 wt%의 높은 담지량과 97% 이상의 담지 효율을 가지면서 물속에서 70 nm의 크기의 안정한 유용 약물 담지 고분자 나노입자를 제조할 수 있었다.

공정안전용 Polymer Blend형 습도센서의 특성 연구 (Preparation and Properties of Polymer Blends Type Humidity Sensor for Process Safety)

  • 강영구;조명호
    • 한국안전학회지
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    • 제19권3호
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    • pp.51-56
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    • 2004
  • Conductive polymer blends and composites are widely used for different safety application such as electrostatic charge dissipation(ESD), electromagnetic interference(EMI) shielding, electrostatic prevention and safety chemical sensor. In order to prepare a impedance-type humidity sensor that is durable at high humidities and high temperature, electically conductive polymer blends based on diallyldimethylammonium chloride(DADMAC) and epoxy were prepared in this study. The polymer blends type conductive ionomer exhibits reaction each other DADMAC and epoxy in FT-IR and DSC analysis. The blends material was traced by new peak at 1600cm-1 and appeard improvement of thermal resistance by melting point shift. Alumina substrate was deposited a pair of gold electrodes by screen printing. The blend material were spin-coated with a thin film type on the surface of alumina substrate. The polymer bleld type sensor exhibits a linear impedance increasing better than DADMAC coated humidity sensor. Also it shows good sensitivity, low hysteresis and durability against high humidity.

Low-operating voltage Pentacene FETs with High dielectric constant polymeric gate dielectrics and its hyteresis behavior

  • Park, Chan-Eon
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.168-168
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    • 2006
  • Low-operating voltage organic field-effect transistors (OFETs) have been realized with high dielectric constant (${\kappa}$) polymer such as cyanoethylated poly vinyl alcohol (CR-V, ${\kappa}=12$). Since the $high-{\kappa}$polymers are likely to contain water and ionic impurities, large hysteresis and considerable leakage current are frequently observed in OFETs. To solve these problems, we cross-linked the CR-V by using a cross-linking agent. Cross-linked CR-V dielectrics showed high dielectric constant of 11.1 and good insulating properties, resulting in a high capacitance ($81nF/cm^{2}$ at 1MHz) at 120 nm of dielectric thickness. Pentacene FETs with cross-linked CR-V dielectrics exhibited high carrier mobility ($0.72\;cm^{2}/Vs$), small subthreshold swing (185 mV/dec) and little hysteresis at low-operating voltage (${\Leq}-3V$).

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분말형 폴리머 혼화제를 적용한 고강도.고차수성 레디믹스트 숏크리트의 물리적 성능 평가 (Evaluation of Physical Performance of High-Strength.High Waterproof Ready-mixed Shotcrete using Powdered Polymer Dispersion)

  • 마상준;최희섭;이흥수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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    • pp.337-340
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    • 2008
  • As the Ready-mixed Shotcrete using Powdered Polymer Dispersion, Shotcrete Matrix as totally shotcrete gel that a part of second binder in Shotcrete materials is dense. Also, Ready-mixed Shotcrete is showed the decreasing Rebound and rising Durability. Therefore, it is possible that Ready-mixed Shotcrete for High-Strength and High-Waterproof can apply to the Powdered Polymer Dispersion.

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VAE 분말수지가 고강도 폴리머 시멘트 모르타르의 강도 특성에 미치는 영향 (Effect of VAE Type Powder Polymer on Strength Properties of High Strength Polymer Cement Mortars)

  • 최중구;이건철;고경택;류금성
    • 한국건축시공학회지
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    • 제15권3호
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    • pp.299-306
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    • 2015
  • 현재 건축분야에서는 시멘트 혼화용 폴리머를 혼입한 연구가 진행되고 있는 상황이다. 하지만 대부분의 연구는 보통강도 배합을 대상으로 연구가 진행되고 있다. 따라서 본 연구에서는 고강도 배합과 보통강도 배합에 VAE 계열의 분말형 폴리머를 혼입하여 고강도 폴리머 시멘트 모르타르의 강도 특성 및 역학적 성질을 검토하고자 하였다. 실험결과, 고강도 배합의 경우 VAE 폴리머 적용 시 폴리머 혼입양이 증가할수록 보통강도 배합에 비해 압축강도 및 휨강도가 감소하는 단점을 나타내지만, 폴리머필름 형성으로 인하여 인장강도 및 부착강도가 향상되는 장점을 나타내었다.