• 제목/요약/키워드: Vinylidene fluoride

검색결과 205건 처리시간 0.023초

Structural Characteristics of Spray-coated Poly (vinylidene fluoride) Thin Films Prepared with Different Organic Solvents

  • 정낙천;임영택;이선우;신백균
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.392.2-392.2
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    • 2014
  • Poly (vinylidene fluoride) thin films were deposited by a spray-coating technology. Two organic solvents with different boiling point were used to prepare the mixture solution for spray coating process: N-Methylpyrrolodone ($B.P.=202^{\circ}C$); Tetrahydrofuran ($B.P.=66^{\circ}C$). Post-deposition annealing temperature was varied for the spray-coated Poly(vinylidene fluoride) thin films. Structural characteristics of the thin films were comparatively investigated by FT-IR and XRD in relation with the organic solvent and post-deposition annealing temperature.

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외부 전장이 Poly(ethylene Oxide)의 등온결정화에 미치는 영향 (Effect of External Electric Field on the Isothermal Crystallization of Poly(ethylene Oxide))

  • 김영호;최재원;김갑진
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2001년도 가을 학술발표회 논문집
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    • pp.271-274
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    • 2001
  • 최근 압전성 및 유전성, 비선형 광학전도성 등과 같은 특성을 갖는 전기전자 및 광기능성 고분자에 대한 연구가 많이 이루어지고 있다[1-2]. 그 중에서 압전 및 초전성을 나타내는 대표적 유기 고분자인 poly(vinylidene fluoride)(PVDF)의 경우 압전성을 향상시키기 위하여 vinylidene. fluoride(VDF)나 vinyl fluoride(VF), trifluoroethylene(TrFE) 등과 공중합시킨 고분자들에 대한 연구가 활발히 진행되어 왔다[3-4]. (중략)

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알칼리 표면개질에 의한 poly(vinylidene fluoride) 섬유의 물리적 성질 (Physical Properties of Poly(vinylidene fluoride) Fibers by Alkaline Surface Modification)

  • 정용채;정민;이선화;조재환
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2002년도 봄 학술발표회 논문집
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    • pp.437-438
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    • 2002
  • Poly(vinylidene fluoride)(PVDF)는 우수한 화학적 특성을 갖는 불소계 고분자로서 엔지니어링 플라스틱, 압전성 소재 및 봉합사용 소재로 이용되고 있다. 최근에는 PVDF의 화학적 개질을 통하여 전도성 고분자나 탄소섬유화 등의 기능성 소재로 만들려는 연구가 흥미롭게 이루어지고 있다. PVDF를 알칼리 처리하여 주쇄에 공액이중결합을 도입함으로써 전도성 고분자용 소재 또는 접착력이 개선된 PVDF 소재를 만들 수 있다. (중략)

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Poly (Vinylidene Fluoride) 박막의 절연파괴와 온도의존성 (Dependence of Dielectric breakdown of Thin Poly (Vinylidene Fluoride) Film on Temperature)

  • 김동욱;박대희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1989년도 하계종합학술대회 논문집
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    • pp.380-382
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    • 1989
  • Dielectric breakdown strength (Eb) of thin Poly(Vinylidene Fluoride ; PVDF) film is studied in the temperature range between 4.2 K and 400 K. The results of this study can be summerized as follows. 1) Temperature dependence of dielectric breakdown strength (Eb) can be devided into high and low temperature regions. The critical temperature (Tc) at which two regions are devided depends on applied voltage. 2) Dielectric breakdown strength (Eb) by pulse voltage is higher than that by DC voltage. Especially this difference is remarkable at low temperature.

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The rheological properties of poly(vinylidene fluoride-co-hexafluoropropylene) solutions in dimethyl acetamide

  • Lee, Ki-Hyun;Song, In-Kyu;Kim, Byoung-Chul
    • Korea-Australia Rheology Journal
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    • 제20권4호
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    • pp.213-220
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    • 2008
  • The effects of temperature on the rheological properties of the solutions of poly(vinylidene fluoride-co-hexafluopropylene) (PVDF-HFP) in dimethyl acetamide (DMAc) were investigated in terms of frequency and concentration. The effects of temperature on the intrinsic viscosity of the solutions were discussed. In dynamic rheological measurement, the concentrated solutions showed a little unexpected rheological response; as temperature was increased dynamic viscosity was increased and the solutions exhibited more noticeable Bingham body character over the temperature range, 30 to $70^{\circ}C$. In addition, the solution gave longer relaxation time, lower value of loss tangent and higher value of yield stress at higher temperature and at higher concentration. On the other hand, the dilute solutions revealed that intrinsic viscosity was decreased and its Huggins constant was increased with increasing temperature. These physical parameters suggested that the increase of viscosity with increasing temperature resulted from the localized gelation of PVDF-HFP due to reduced solubility to the solvent.

Analysis of the Wettability of Partially Fluorinated Polymers Reveals the Surprisingly Strong Acid-Base Character of Poly(vinylidene Fluoride)

  • Lee, Sang-Wha;Park, Joon-Seo;Lee, T. Randall
    • Bulletin of the Korean Chemical Society
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    • 제32권1호
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    • pp.41-48
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    • 2011
  • The wettabilities of the partially fluorinated polymers (ethylene-tetrafluoroethylene copolymer (ETFE), ethylenechlorotrifluoroethylene copolymer (ECTFE), and poly(vinylidene fluoride) (PVDF)) were investigated by contact angle measurements. Zisman plots for ETFE and ECTFE exhibited linear relationships, while the Zisman plot for PVDF showed a slight curvature, which was interpreted to indicate strong non-dispersive interactions between the surface and the contacting liquids. The Lifshitz-van der Waals forces of the fluoropolymers were estimated to increase in the order of ETFE < PVDF $\ll$ ECTFE. An evaluation of the polar or "acid-base" interaction energies showed that PVDF, which possesses the most acidic hydrogens among the examined fluoropolymers, has the strongest acid-base interactions.

$^{60}Co\;\gamma$-선 조사에 의한 Poly(Vinylidene fluoride)의 구조적 변화 (Structural Changes in $^{60}Co\;\gamma-Ray$ Irradiated Poly(vinylidene fluoride))

  • 이청;김기엽;김평종;김진아;류부형
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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    • pp.437-440
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    • 2004
  • The radiation-induced changes taking place in poly(vinylidene fluoride)(PVDF) exposed to $^{60}Co\;\gamma-ray$ irradiation were investigated in correlation with the applied doses. Samples were irradiated in air at room temperature by $^{60}Co\;\gamma-ray$ to doses in the range of 200 to 1000 kGy. Various properties of the irradiated PVDF were studied using nm, differential scanning calorimetry(DSC) and gel fraction. $^{60}Co\;\gamma-ray$ irradiation was found to induce changes in chemical, thermal, structural properties of PVDF and such changes vary depending on the radiation dose.

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