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1997 Fiscal Year Final Research Report Summary

Studies on the Formatio Mechamisms and Functionality Properties of Single Crystalline Flims of Ferroelectic Polymers

Research Project

Project/Area Number 08455448
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field 高分子構造・物性(含繊維)
Research InstitutionYamagata University

Principal Investigator

OHIGASHI Hiroji  Yamagata University, Faculty of Engineering, Porofessor, 工学部, 教授 (90185372)

Co-Investigator(Kenkyū-buntansha) KOGA Keiko  Kyushu Sango University, Faculty of Engineering, Research Associate, 工学部, 助手 (90234723)
TAJITSU Yoshiro  Yamagata University, Faculty of Engineering, Assistant Porofessor, 工学部, 助教授 (00282236)
Project Period (FY) 1996 – 1997
KeywordsFerroelectric Polymer / Piezoelectric Polymer / Single Crystalline Film / P (VDF / TrFE) / Polymer Blend / Moelecular Chain Motion / Ultrasonic Transducer / Electro-optical Effect
Research Abstract

We previously found that ferroelectric copolymer of vinylidene fluoride and trifluoroethylene, P (VDF/TrFE), crystallizes into a highly crystallized, and highly double-oriented film, which we call a single crystalline (SC) film. The SC film is best material to investigate anisotropic properties of polymer crystals, because it do not have amorphous phase nor lamellar crystals. In this research project we have studied (i) the structure of SC film and its formation mechanisms, (ii) the origin of anormalous dielectric behavior apperaring above the Curie temperature, from the standpoint of molecular chain motions in the paraelectric phase, (iii) piezoelectric properties and its application to shear wave ultrasonic transducers, and (iv) electro-optical properties.
The results obtained are as follows. (1) The SC film in the orthormbic phase is a twin crystal, whose c-axis orients parallel to the stretching axis, and the b-axis (polar axis) orients 300 off the film normal. In the paraelectric p … More hase it becomes a hexagonal single crystal, the hexagonal [100] axis being normal to the film surface. The preferential orientation of the crystal axes is developed in the paraelectric (hexagonal) phase, which is due to the lowest free surface energy of the (100) plane in the hexagonal phase. (2) The molecular chain motion in the paraelectric phase was revealed by X-ray diffraction and dielectric relaxation measurements : each chain molecule of TGTG' conformation undergoes the flip-flop motion and rotational motion independently of neighboring chain molecules in the hexagonal crystal, a crystal having liquid crystal characteristic. Based on these information we establish to a new concept to explain the anomalous dielectric properties appearing in the paraelectric phase. (3) The SC film is found to have very effective shear piezoelectricity. We developed transducers for transverse ultrasonic waves, which have been proved to be practically useful for non-destractive inspection of industrial materials. (4) The electrooptical property (Pockels effect) was measured. The result shows the film to be a potential material for electrooptical devices.
In addition to the above mentioned results, we have obtained some useful and interesting results on the structure and properties of oriented films of (a) P(VDF/TrFE)/PMMA blends, (b) high pressure crystallized P(VDF/TrFE)/PVDF and (c) high pressure crystallized polyethylene. Less

  • Research Products

    (17 results)

All Other

All Publications (17 results)

  • [Publications] T.Hattori: "Improved piezoelectricity in thick lamellar b-form crystals of poly(vinylidene fluorede)crystallized under high pressure" J.Appl.Phys.79. 2018-2022 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Hattori: "Crystallization behaviour and phase diagram of extended chain crystals of poly (vinylidene- fluoride)" Polymer. 37. 85-91 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] K.Omote: "Properites of transverse ultrasonic transducers of ferroelectric polymers working in thickness shear modes" IEEE Trans.Ultrason.Ferroelect.Freq.Cont.43. 312-318 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] K.Omote: "Shear Piezoelectric Constant of Polarized Polyvinylidene Fluoride Studied by the Piezoelectric Resonance Method." Jpn.J.Appl.Phys.35. 1818-1823 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] K.Omote: "Temperature Dependence of elastic,pielectric and piezoelectric properties of “Single Crystalline" film of vinylidene fluoride trifluoroethylene copolymer" J.Appl.Phys.81. 2760-2769 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Hattori: "High-pressure crystallization behaviors and piezoelectricity of extended chain lamellar crystals of P(VDF/TrFE) copolymers with high molar content of vinylidene fluoride" Polymer. 38. 3505-3511 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 古賀啓子: "フッ化ビニリデン-三フッ化エチレン共重合体単結晶状膜における結晶サイズと乱れ" 九州産業大学工学部研究報告. 35. 137-142 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] H.Ohigashi: "Chain Motions in the Paraelectric Phase in Single Crystalline Films of Vinylidene Fluoride and Trifluoroethylene Copolymer P(VDF/TrFE)" J.Phys.Soc.Japan. (掲載予定).

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] H.Ohigashi: "Ferroelectric Polymer Transducers for Transverse Ultrasonic Waves" The 1998 IEEE Intern.Ultrasonics Symp.Proceedings. (掲載予定).

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] H.Ohigashi: "Structure of Single Crystalline Films of Vinylidene Fluoride and Trifluoroethylene Copolymers" Polymer J. to be submitted.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] H.Ohigashi: "Anisotropic Molecular Motions in the Paraelectric Phase of Vinylidene Fluoride and Trifluoroethylene Ferroelectric Copolymers as Studied by an AT-cut Quartz Resonator" J.Appl.Phys. to be submitted.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Tajitsu: "Pockels effects of Ferroelectric Thin Films of Vinylidene Fluoride and Trifluoroethylene Copolymeers"" J.Materials Sci.Lett.16. 1378-1380 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Tajitsu: "Electrooptical Effects of“Single-Crystalline" Films of Ferroelectric Copolymers of Vinylidene Fluoride and Trifluoroethylene" Jpn.J.Appl.Phys.36. L693-695 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Tajitsu: "Ferroelectric Switching Behaviour in Thin films of Polyurea-5," Japan.J.Appl.Phys.36. L791-793 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Tajitsu: "Optical Behavior of Ferroelectric “Single Crystalline" Films of Vinylidene Fluoride and Trifluoroethylene Copolymers" Ferroelectrics. 218. 103-113 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 大東弘二(分担執筆): "超音波ハンドブック" 丸善出版(印刷中), (1999)

    • Description
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  • [Publications] "静電気材料,静電気ハンドブック" オーム社, 1294 (1998)

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Published: 1999-12-08  

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