Thermal Contraction and Ferroelectric Phase Transition in Vinylidene Fluoride-Trifluoroethylene Copolymers. 2. An Effect of Tensile Stress Applied in the Direction Perpendicular to the Chain Axis

Kohji Tashiro, Shin Nishimura, Masamichi Kobayashi

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19 Citations (Scopus)

Abstract

Anisotropic thermal expansion under externally applied tensile stress has been measured for uniaxially oriented ferroelectric vinylidene fluoride-trifluoroethylene (VDF-TrFE) copolymers with VDF 65% molar content. In the heating (cooling) process, the sample length along the drawing direction was found to contract (expand) largely in the vicinity of the structural phase transition temperature, while the dimension in the direction perpendicular to the draw axis has been found to expand (contract) in the same temperature region. The unoriented film exhibited a thermal expansion behavior intermediate between the dimensional changes in the parallel and perpendicular directions. A comparison of these thermomechanical curves with the data of X-ray, infrared and Raman, DSC, etc., revealed that the bulk dimensional changes of the sample reflect directly the structural phase transition occurring in the crystalline region in both directions. The transition temperature was found to shift to the lower side with an increasing applied stress: ΔT/Δσ- = -1.0 K/MPa (perpendicular) and -4.6 K/MPa (parallel). These results were interpreted reasonably based on a modified thermodynamical Clausius-Clapeyron equation.

Original languageEnglish
Pages (from-to)2802-2806
Number of pages5
JournalMacromolecules
Volume23
Issue number10
DOIs
Publication statusPublished - Jan 1 1990
Externally publishedYes

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Tensile stress
Superconducting transition temperature
Ferroelectric materials
Thermal expansion
Copolymers
Phase transitions
Crystalline materials
Cooling
Infrared radiation
Heating
X rays
Temperature
Hot Temperature
Direction compound
vinylidene fluoride-trifluoroethylene copolymer

All Science Journal Classification (ASJC) codes

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

Cite this

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title = "Thermal Contraction and Ferroelectric Phase Transition in Vinylidene Fluoride-Trifluoroethylene Copolymers. 2. An Effect of Tensile Stress Applied in the Direction Perpendicular to the Chain Axis",
abstract = "Anisotropic thermal expansion under externally applied tensile stress has been measured for uniaxially oriented ferroelectric vinylidene fluoride-trifluoroethylene (VDF-TrFE) copolymers with VDF 65{\%} molar content. In the heating (cooling) process, the sample length along the drawing direction was found to contract (expand) largely in the vicinity of the structural phase transition temperature, while the dimension in the direction perpendicular to the draw axis has been found to expand (contract) in the same temperature region. The unoriented film exhibited a thermal expansion behavior intermediate between the dimensional changes in the parallel and perpendicular directions. A comparison of these thermomechanical curves with the data of X-ray, infrared and Raman, DSC, etc., revealed that the bulk dimensional changes of the sample reflect directly the structural phase transition occurring in the crystalline region in both directions. The transition temperature was found to shift to the lower side with an increasing applied stress: ΔT/Δσ- = -1.0 K/MPa (perpendicular) and -4.6 K/MPa (parallel). These results were interpreted reasonably based on a modified thermodynamical Clausius-Clapeyron equation.",
author = "Kohji Tashiro and Shin Nishimura and Masamichi Kobayashi",
year = "1990",
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T1 - Thermal Contraction and Ferroelectric Phase Transition in Vinylidene Fluoride-Trifluoroethylene Copolymers. 2. An Effect of Tensile Stress Applied in the Direction Perpendicular to the Chain Axis

AU - Tashiro, Kohji

AU - Nishimura, Shin

AU - Kobayashi, Masamichi

PY - 1990/1/1

Y1 - 1990/1/1

N2 - Anisotropic thermal expansion under externally applied tensile stress has been measured for uniaxially oriented ferroelectric vinylidene fluoride-trifluoroethylene (VDF-TrFE) copolymers with VDF 65% molar content. In the heating (cooling) process, the sample length along the drawing direction was found to contract (expand) largely in the vicinity of the structural phase transition temperature, while the dimension in the direction perpendicular to the draw axis has been found to expand (contract) in the same temperature region. The unoriented film exhibited a thermal expansion behavior intermediate between the dimensional changes in the parallel and perpendicular directions. A comparison of these thermomechanical curves with the data of X-ray, infrared and Raman, DSC, etc., revealed that the bulk dimensional changes of the sample reflect directly the structural phase transition occurring in the crystalline region in both directions. The transition temperature was found to shift to the lower side with an increasing applied stress: ΔT/Δσ- = -1.0 K/MPa (perpendicular) and -4.6 K/MPa (parallel). These results were interpreted reasonably based on a modified thermodynamical Clausius-Clapeyron equation.

AB - Anisotropic thermal expansion under externally applied tensile stress has been measured for uniaxially oriented ferroelectric vinylidene fluoride-trifluoroethylene (VDF-TrFE) copolymers with VDF 65% molar content. In the heating (cooling) process, the sample length along the drawing direction was found to contract (expand) largely in the vicinity of the structural phase transition temperature, while the dimension in the direction perpendicular to the draw axis has been found to expand (contract) in the same temperature region. The unoriented film exhibited a thermal expansion behavior intermediate between the dimensional changes in the parallel and perpendicular directions. A comparison of these thermomechanical curves with the data of X-ray, infrared and Raman, DSC, etc., revealed that the bulk dimensional changes of the sample reflect directly the structural phase transition occurring in the crystalline region in both directions. The transition temperature was found to shift to the lower side with an increasing applied stress: ΔT/Δσ- = -1.0 K/MPa (perpendicular) and -4.6 K/MPa (parallel). These results were interpreted reasonably based on a modified thermodynamical Clausius-Clapeyron equation.

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