• Title, Summary, Keyword: Polymer

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Synthesis and Characterization of a Tetrathiafulvalene-Based Polymer

  • Lee, Se-Hyun;Wang, Lei;Hwang, Seok-Ho;Lee, Myong-Hoon;Jeong, Kwang-Un
    • Bulletin of the Korean Chemical Society
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    • v.33 no.5
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    • pp.1451-1456
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    • 2012
  • A novel tetrathiafulvalene (TTF)-based main-chain polymer (6TTF-polymer) was successfully synthesized via a condensation polymerization between a newly synthesized dihydroxy TTF derivative and a malonyl chloride, and its chemical structure was characterized by spectroscopic techniques. Molecular weight of the 6TTF-polymer (9,030 g/mol by gel permeation chromatography) was large enough to form the ductile film. The electrochemical and optical properties of the 6TTF-polymer were further estimated by cyclic voltammetry, ultraviolet and photoluminescence spectroscopes. The highest occupied molecular orbital level ($E_{HOMO}$=-4.79 eV) and band-gap energy ($E_g$=1.91 eV) of the 6TTF-polymer suggested that TTF-based polymer could act as a good electron donating material for the optoelectronic applications.

Drying Shrinkage of Ultrarapid-Hardening Polymer-Modified Mortar Using Redispersible Polymer Powder (재유화형 분말수지를 혼입한 초속경 폴리머 시멘트 모르타르의 건조수축)

  • 이윤수;주명기;정인수
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.93-98
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    • 2002
  • The effects of polymer-cement ratio, antifoamer content and shrinkage-reducing agent content on the air content, setting time and drying shrinkage of polymer-modified mortars using redispersible polymer powder are examined. As a result the air content of the polymer-modified mortars using redispersible polymer powder tend to decrease with increasing polymer-cement ratio and antifoamer agent content. Regardless of the antifoamer content, the setting time of the polymer-modified mortars using redispersible polymer powder tend to delayed with increasing polymer-cement ratio. Irrespective of the antifoamer content, the drying shrinkage of the polymer-modified mortars using redispersible polymer powder tend to decrease with increasing polymer-cement ratio and shrinkage-reducing agent content.

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A Study on the Mechanical Properties and Permeability of Permeable Polymer Concrete Covered with Polymer Mortar as a Filter (폴리머 모르터를 필터로 사용한 투수성 폴리머 콘크리트의 역학적 성질과)

  • 박응모;조영국;소양섭
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.237-242
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    • 1998
  • Covering mortar as a filter for permeable polymer concrete is necessary for good permeability from filtration continuously. Therefore, this paper is intended as an evaluation of the mechanical properties and permeability of permeable polymer concrete covered with polymer mortar as a filter. An optimum permeable polymer concrete is selected in various mix proportions, and three different polymer mortars were cast immediately following on the casting of the base permeable polymer concrete. And they are tested for compressive and flexural strengths, adhesion in tension, hardening shrinkage and permeability . From the test results, binder and filler contents in mix proportions had a great influence on the permeability of polymer concretes. The mechanical properties of permeable polymer concretes covered with polymer mortars using crushed stone are superior to other filters, and hardening shrinkage is the smallest in filters. It is apparent that adhesion between the base permeable polymer concrete and polymer mortar is affected by the degree of hardening shrinkage. From this study, proper mix proportions can be recommended in the consideration of properties of the permeable polymer concrete.

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Strength Properties of Polymer-Modified Mortars Using Redispersible Polymer Powders (재유화형 분말수지를 이용한 폴리머 시멘트 모르터의 강도특성)

  • 김완기;형원길;소양섭
    • Proceedings of the Korean Institute of Building Construction Conference
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    • pp.88-92
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    • 2001
  • This paper discusses the strength properties of the polymer-modified mortars using redispersible polymer powders, which is widely used for the manufacture of prepackaged-type polymer-modified mortar products at present. The polymer-modified mortars using redispersible polymer powders are prepared with various polymer-cement ratios, and tested for air content, flexural and compressive strengths, and tensile strength. The strength properties are almost the same as those of polymer dispersion-modified mortars, depending on the polymer-cement ratios, and are improved over unmodified mortar. In particular, between tensile strength and glass transition point of polymer powder have a high correlation. It is concluded from the test results that polymer-modified mortars using redispersible polymer powders can be used in the same manner as ordinary polymer dispersion-modified mortars.

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Synchrotron Grazing Incidence X-ray Scattering and Its Applications in Polymer Nanotechnology

  • Ree, Moon-Hor;Lee, Byeong-Du;Yoon, Jin-Hwan;Heo, Kyu-Young;Jin, Kyeong-Sik;Jin, Sang-Woo;Kim, Hyun-Chul;Kim, Gha-Hee;Choi, Seung-Chul;Oh, Weon-Tae;Park, Young-Hee;Hwang, Yong-Taek;Kim, Jong-Seong
    • Proceedings of the Polymer Society of Korea Conference
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    • pp.120-120
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    • 2006
  • In our study grazing incidence X-ray scattering (GIXS) measurements with synchrotron radiation sources were conducted statically and in-situ for a series of nanoscale thin films prepared from nanoporous dielectrics, block copolymers, brush polymers, and molecular assemblies. All GIXS measurements were performed at the Pohang Accelerator Laboratory. The measured scattering data were analyzed in detail by using newly developed GIXS scattering theory. All GIXS results will be discussed in details with considering the materials chemistry and nanostructure formation process parameters.

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Properties of Strength of Ultrarapid-Hardening Polymer-Modified Mortar (초속경 폴리머 시멘트 모르타르의 강도특성)

  • Lee, Youn-Su;Joo, Myung-Ki;Yeon, Kyu-Seok
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • pp.115-118
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    • 2001
  • The effects of polymer-cement ratio and shrinkage-reducing agent content on the strength properties of ultrarapid-hardening polymer-modified mortars using redispersible polymer powder are examined. As a result, the flexural and tensile strengths of the ultrarapid-hardening polymer-modified mortars using redispersible polymer powder tend to increase with increasing polymer-cement ratio, and tend to decrease with increasing shrinkage-reducing agent content. However, the compressive strength of the ultrarapid-hardening polymer-modified mortars using redispersible polymer powder decrease with increasing polymer-cement ratio and shrinkage-reducing agent content.

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Abnormal Behavior in Color Tracking in the Fringe-Field Switching (FFS) Liquid Crystal Display

  • Jung, Jun-Ho;Ha, Kyung-Su;Chae, Mi-Na;Cho, In-Young;Kim, Woo-Il;Kim, Dae-Hyun;Kim, Sung-Min;Lee, Seung-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.616-619
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    • 2009
  • Color tracking behavior of in the fringe-field switching (FFS) mode using a liquid crystal with positive dielectric anisotropy has been studied. In the in-plane switching and vertical alignment devices, color chromaticity at normal direction changes from bluish to yellowish white linearly with increasing grey levels from dark to white state. Interestingly, abnormal behavior in color tracking is observed in FFS devices using a liquid crystal with positive dielectric anisotropy, that is, it changes from bluish to yellowish up to a certain middle grey level but turns over to bluish white with further increasing from a grey level to a fully white state. In this paper, we analyze this abnormal effect from the calculated and experimental results.

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Frustration of Rod-Disc Molecule in Reorientation under Vertical Electric Field

  • Jung, Jun-Ho;Ha, Kyung-Su;Chae, Mi-Na;Park, Seul-Ki;Song, Eun-Gyoung;Lee, Myong-Hoon;Jeong, Kwang-Un;Lee, Seung-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.610-613
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    • 2009
  • New rod-disc liquid crystal (LC) molecule RD12 (12 is the number of carbon atoms between the rod and disc mesogenic liquid crystals) was synthesized via the chemical attachment of six cyanobiphenly calamitic mesogens linked to the triphenyl discotic mesogen with six alkyl chain linkage. Aligning characteristics associated with homogenous alignment is investigated at first and then field-dependent molecular reorientation under a vertical electric field is studied. Interestingly, they show abnormal slow molecular transition from initiate state (no electric field condition) to certain voltage. In this condition, we observe the molecular competition during reorientation. However, once a tilting direction of disk molecules are defined, the frustration is not observed anymore. The origin of this phenomenon is explained with a suggested model for the first time.

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