• Title/Summary/Keyword: High Polymer

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Manipulating Anisotropic Filler Structure in Polymer Composite for Heat Dissipating Materials: A Mini Review (방열소재로의 응용을 위한 고분자 복합소재 내 이방성 필러 구조 제어 연구동향)

  • Seong-Bae, Min;Chae Bin, Kim
    • Composites Research
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    • v.35 no.6
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    • pp.431-438
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    • 2022
  • Efficient heat dissipation in current electronics is crucial to ensure the best performance and lifespan of the devices along with the users' safety. Materials with high thermal conductivity are often used to dissipate the generated heat from the electronics to the surroundings. For this purpose, polymer composites have been attracted much attention as they possess advantages rooted from both polymer matrix and thermally conductive filler. In order to meet the thermal conductivity required by relevant industries, composites with high filler loadings (i.e., >60 vol%) have been fabricated. At such high filler loadings, however, composites lose benefits originated from the polymer matrix. To achieve high thermal conductivity at a relatively low filler loading, therefore, constructing the heat conduction pathway by controlling filler structure within the composites may represent a judicious strategy. To this end, this review introduces several recent approaches to manufacturing heat dissipating materials with high thermal conductivity by manipulating thermally conductive filler structures in polymer composites.

Thermal Decomposition and Mechanical Properties of Polycarbonate/ABS Blends Prepared by High Shear Rate Processing (고속전단에 의한 폴리카보네이트/ABS 블렌드의 열분해 및 기계적 특성 연구)

  • Yoo, Jae Jung;Yong, Da Kyoung;Lee, Han Ki;Kim, Dae Sik;Lee, Hyung Il;Kim, Sun Hong;Lee, Kee Yoon;Lee, Seung Goo
    • Polymer(Korea)
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    • v.38 no.4
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    • pp.471-476
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    • 2014
  • Polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) blends were prepared using a high shear extruder to investigate their thermal decomposition and mechanical properties with shear rate and shear time. In this experiment, high shear rate, from 1000 to 3000 rpm, in blending process was applied for 10 to 40 sec, respectively. At high shear rate over than 2000 rpm, the initial decomposition temperature was dropped significantly compared to a compounded sample because of thermal decomposition of the blend by high shear. Consequently, high shear processing gave an important effect on the mechanical and thermal properties of the PC/ABS blend. In particular, elongation of the blend decreased significantly with shear rate.

Chemical and Electrochemical Synthesis of Highly Conductive and Processable PolyProDOP-alkyl Derivatives

  • Cho, Youn-Kyung;Pyo, Myoung-Ho;Zong, Kyu-Kwan
    • Journal of the Korean Electrochemical Society
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    • v.13 no.1
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    • pp.57-62
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    • 2010
  • New monomers, possessing various alkyl substituents on propylene dioxypyrrole, were synthesized. The monomers could be easily polymerized to produce highly conductive and soluble polymers. The corresponding polymers showed excellent solubility, retaining electrochemical and optical properties of their parent polymer [poly(propylene dioxypyrrole)]. The conductivities of chemically prepared polymers were quite high in a range of 20 and $60\;Scm^{-1}$. Solubility of the polymer in a common organic solvent was as high as no polymer is deposited on an electrode. The redox potentials of the electrochemically prepared polymers revealed quite stable electro-activity during repeated redox switching up to 500 times. The optoelectrochemistry studies also showed distinct color changes of the polymers upon changing the doping state, indicating strong absorption peaks at 400~600 nm in reduced states and complete bleaching in fully oxidized states.

Charge Transport in Uniaxially Aligned Liquid-crystalline Polymer Transistors

  • Lee, Mi-Jeong;Chen, Zhuoying;Sirringhaus, H.;Lee, Jang-Sik
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.10a
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    • pp.27.2-27.2
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    • 2011
  • Polymer electronics is the one of the most promising way to realize the flexible electronics and many studies made remarkable progress to achieve the improvement in performance of polymer electronics comparable to current silicon-based technology. PBTTT is conjugated semiconducting polymer with highly ordered, chain-extended crystalline microstructures and shows high field effect mobilities above 0.1 $cm^2/Vs$. We studied PBTTTs FETs phase and explored methods to control channel interface in various device structures. Especially, in PBTTTs' unique nano-ribbon phase, we could obtain high mobilities of up to 0.4 $cm^2/Vs$, which was not reached before. Alignment of PBTTTs film was carried out using zone casting and anisotropy of mobilities in parallel and perpendicular to the polymer chain direction was investigated. Optical anisotropy in aligned nano-ribbon PBTTT FETs was also studied using a polarized optical absorption.

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Flexural Performance of Reinforced Polymer Concrete Beams with High Strength (철근 보강 고강도 폴리머 콘크리트 보의 휨특성)

  • 연규석;김관호;김기락
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1998.10a
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    • pp.136-141
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    • 1998
  • While a little research has been peformed on flexural behavior of reinforced polymer concrete (RPC)beams with the compressive strength lower than 900kg/$\textrm{cm}^2$ vary little exists in conjunction with the behavior of RPC 1,000kg/$\textrm{cm}^2$ or higher in compressive strength. In this paper the flexural performance of high strength polymer concrete beams with 1,450kg/$\textrm{cm}^2$ in compressive strength was evaluated. The unsaturated polyester resin was used to make polymer concrete as binder. The beams with stirrup singly/doubly were tested to examine the effect of tensile reinforcement ratio. As test results, reinforcement ratio increased with the increase moment strength, decreased with ultimate deflection, ductility index.

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Morphologies and surface properties of cellulose-based activated carbon nanoplates

  • Lee, Seulbee;Lee, Min Eui;Song, Min Yeong;Cho, Se Youn;Yun, Young Soo;Jin, Hyoung-Joon
    • Carbon letters
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    • v.20
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    • pp.32-38
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    • 2016
  • In this study, cellulose nanoplates (CNPs) were fabricated using cellulose nanocrystals obtained from commercial microcrystalline cellulose (MCC). Their pyrolysis behavior and the characteristics of the product carbonaceous materials were investigated. CNPs showed a relatively high char yield when compared with MCC due to sulfate functional groups introduced during the manufacturing process. In addition, pyrolyzed CNPs (CCNPs) showed more effective chemical activation behavior compared with MCC-induced carbonaceous materials. The activated CCNPs exhibited a microporous carbon structure with a high surface area of 1310.6 m2/g and numerous oxygen heteroatoms. The results of this study show the effects of morphology and the surface properties of cellulose-based nanomaterials on pyrolysis and the activation process.

Physical and Mechanical Properties of Polymer Concrete Using Coal Mine Waste (석탄폐석을 이용한 폴리머 콘크리트의 물리.역학적 특성)

  • 연규석;김기성;장태연;정경현;주명기;최동순
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.04a
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    • pp.57-64
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    • 1996
  • Lately, rapid expansion of construction industry and following increment of demand for concrete in the construction created shortage of aggregates in the nation. Supplement of good quality aggregate is an immediate issue for the construction industry to solve. Therefore, this study evaluated a possibility of using coal mine waste collceted from Kwangwon-do region as a source of aggregate in manufacturing polymer concretes which have high strength and high durability. First, aggregates were obtained by crushing coal mine waste and polymer concrete was manufactured using these aggregate. Mechanical property test results for the polymer concrete showed that the coal mine waste aggregates were acceptable to use as a replacement of the aggregate in polymer concrete manufacture.

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Strength Properties of Polymer-Modified Mortar with High-Range Water- Reducing Agents (고성능 감수제를 첨가한 폴리머 시멘트 모르타르의 강도 특성)

  • 이윤수;주명기
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.811-815
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    • 2003
  • The effects of high-range water-reducing agent (WRA) content and polymer-cement ratio on the strength properties of autoclaved SBR-modified mortars with WRA are examined. As a result, the flexural strength of the autoclaved SBR-modified mortars with WRAs tends to increase with increasing WRA content and polymer-cement ratio, and reaches a maximum at a WRA content of 2.0%. The compressive strength of the autoclaved SBR-modified mortars with WRAs is inclined to increase with increasing WRA content and polymer-cement ratio, and reaches a maximum at a WRA content of 2.0% and a polymer-cement ratio of 10%. From the test results, the addition of the WRAs is effective for improving strength properties of the autoclaved SBR-modified mortars.

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Barrier Rib Patterning Technology for Cost Effective High Resolution PDP

  • Park, Lee-Soon;Paek, Sin-Hye;Yun, Sang-Won;Choi, Hyung-Suk
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.989-993
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    • 2002
  • Barrier ribs in the color plasma display panel(PDP) function to maintain the discharge space between to glass plates as well as to prevent optical crosstalk. Patterning of barrier ribs is one of unique processes for making PDP. In this work photosensitive barrier rib pastes were prepared by incorporating binder polymer, solvent, functional monomers photoinitiator, mid barrier rib powder. Study on the function of materials for the barrier rib paste were undertaken. After optimization of paste formulation, both photolithographic and transparent soft molding method resulted in fine pattern of barrier ribs with high aspect ratio.

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Development of Polymer Mortar Protection Block for Erosion Control Works (폴리머 모르터를 이용한 사면보호재의 개발)

  • Ryu, Neung-Hwan;Yeon, Kyu-Seok;Kim, Ki-Sung;Lee, Youn-Su
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.40 no.5
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    • pp.52-58
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    • 1998
  • The objective of this study was to develop a polymer mortar protection block with high strength and durability using unsaturated polyester resin to complement defects of conventional cement mortar protection block. Physical and mechanical properties of the polymer mortar protection block were also investigated. Low absorptivity, high impact strength, and great bending strength of the polymer mortar protection block was compared with those of the conventional cement protection block. In conclusion, the polymer mortar protection block is excellent and useful as industrial products for erosion control works.

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