Microstructure and crystallization of isotropic films made of vinylidene fluoride-tetrafluoro-ethylene copolymer

Kochervinskiĭ, V. V.; Glukhov, V.A.; Соколов, В. Г.; Romadin, V.F.; Murasheva, Ye.M.; Ovchinnikov, Yu.K.; Trofimov, N.A.; Lokshin, B. V.

doi:10.1016/0032-3950(88)90067-6

Cited by 18 publications

(10 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The objects of study were copolymer films of VDF-TFE with a molar ratio of the components of 94 : 6, whose microstructure was previously studied via 19 F NMR [24]. Isotropic films, which were structur ally characterized in [23,24], were prepared via crys tallization from a low boiling solvent (acetone) at ambient temperature.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Polarization of block textured films of ferroelectric copolymers of vinylidene fluoride with tetrafluoroethylene in an external field

et al. 2014

View full text Add to dashboard Cite

The polarization of oriented films of the ferroelectric copolymer of vinylidene fluoride and tet rafluoroethylene in a sinusoidal electric field is studied. In low fields, the copolymer behaves as a linear dielectric whose permittivity nonlinearly increases with the amplitude of the alternating field. This behavior is related to the preferential orientation of the dipole moment of the chain along the normal to the surface and to the monocrystal structure formation. In higher fields, the hysteresis behaves formally coincidently with the behavior of an antiferroelectric. The important role of through stressed chains in the amorphous phase in the initiation of domains of a new direction in polar crystals is observed. Increased adsorption of water molecules on the surface of a polarized film is found and is attributed to the formation of the final den sity of the stable polarization charge on it.

show abstract

Section: Methodsmentioning

confidence: 99%

“…Isotropic films, which were structur ally characterized in [23,24], were prepared via crys tallization from a low boiling solvent (acetone) at ambient temperature. Texturing was performed via monoaxial drawing (up to 6 fold) at 75°С followed by isometric annealing at 125°С.…”

Section: Methodsmentioning

confidence: 99%

Polarization of block textured films of ferroelectric copolymers of vinylidene fluoride with tetrafluoroethylene in an external field

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Their chain microstructure was previously characterized by high resolution NMR. 15,16 The polymer films of VDF/TFE and VDF/TrFE 70/30 copolymers were prepared by crystallization from a solution in acetone. 8 wt.…”

Section: Experimental Partmentioning

confidence: 99%

Influence of parameters of molecular mobility on formation of structure in ferroelectric vinylidene fluoride copolymers

Kochervinskiĭ

Malyshkina

Павлов

et al. 2015

Journal of Applied Physics

View full text Add to dashboard Cite

Articles you may be interested inStructural and dielectric properties of poly(vinylidene fluoride)-based terpolymer/copolymer blends developed on aluminum foil J. Appl. Phys. 112, 053505 (2012); 10.1063/1.4748181 Interacting and noninteracting dipole systems in ferroelectric poly(vinylidene fluoride-trifluoroethylene) copolymer J. Appl. Phys. 108, 084109 (2010); 10.1063/1.3499614 Structural evolution and dielectric relaxation behavior of electron-irradiated poly(vinylidene fluoride-trifluoroethylene) 80/20 mol % copolymers J. Appl. Phys. 94, 5566 (2003); 10.1063/1.1606853 Infrared spectroscopic ellipsometry study of vinylidene fluoride (70%)-trifluoroethylene (30%) copolymer Langmuir-Blodgett films J. Appl. Phys. 94, 195 (2003); 10.1063/1.1578697Dielectric relaxation behavior and its relation to microstructure in relaxor ferroelectric polymers: High-energy electron irradiated poly(vinylidene fluoride-trifluoroethylene) copolymersThe low-temperature molecular mobility has been studied by dielectric relaxation spectroscopy on the bulk films of statistic copolymers of vinylidene fluoride (VDF) with tetra-(TFE) and trifluoroethylene obtained by crystallization from a solution in acetone. The results show that activation energy of the kinetic units in the glassy state depends significantly on the concentration of polar groups. The cooperative mobility above the glass transition temperature is described by Vogel-Tamman-Fulcher equation; the lowest value of the effective activation energy was found in the copolymer with highest amount of non-polar TFE content. It has been shown that the parameters of the dynamics are related to the structural parameters obtained by infrared spectroscopy, wide-angle X-ray Spectroscopy, and small-angle X-ray scattering. In particular, the largest crystals and the highest value of the "large" period have been detected in VDF/TFE copolymer with lowest activation parameters of microbrownian and local mobility. Number of lamellar crystals in stacks is determined by the concentration of VDF polar groups in copolymer chain. V C 2015 AIP Publishing LLC.

show abstract

“…2). It should be remembered, however, that copolymer #2 is characterized by lower coercive fields than copolymer #1 [11,12]. This fact should also be considered when analyzing the field dependence of highvoltage conductivity.…”

Section: Samples and Experimental Techniquesmentioning

confidence: 96%

“…Samples of a VDF-TFE copolymer with a molar composition of 94:6 (sample #1) and 71:29 (sample #2) were studied; the microstructure of the copolymer was previously characterized via a 19 F NMR technique [11,12]. The fraction of head-tohead (HHTT) chemical defects in the studied copolymer #1 is 4.2 mol%.…”

Section: Samples and Experimental Techniquesmentioning

confidence: 99%

Local piezoelectric response, structural and dynamic properties of ferroelectric copolymers of vinylidene fluoride–tetrafluoroethylene

et al. 2014

View full text Add to dashboard Cite

The characteristics of the local piezoelectric response of isotropic films of copolymers of vinylidene fluoride (VDF) were compared with 6 and 29 mol% tetrafluoroethylene (TFE) obtained by crystallization from a solution in acetone. Time dependence of the electric displacement response was analyzed after switching of the spontaneous polarization. A copolymer with a higher content of tetrafluoroethylene is characterized by higher values of electrical displacement and piezoelectric response. For interpretation of this fact, we used molecular mobility in amorphous phase dates. It is shown that the activation energy of local and cooperative liquid-like (in the amorphous phase) mobility is markedly lower in the copolymer with a higher content of TFE. Under identical conditions of the crystallization, both films of the copolymers lead to the formation of larger crystals of the polar phase and magnitude of a "long" period at a high content of copolymer of TFE. It is postulated that these structural parameters are responsible for the stable value of residual local piezoelectric activity. It is found that the rapid decay of the signal in the local piezoresponse of polarized films is controlled by the activation energy of the local and cooperative dynamics chains of the amorphous phase.

show abstract

Microstructure and crystallization of isotropic films made of vinylidene fluoride-tetrafluoro-ethylene copolymer

Cited by 18 publications

References 17 publications

Polarization of block textured films of ferroelectric copolymers of vinylidene fluoride with tetrafluoroethylene in an external field

Polarization of block textured films of ferroelectric copolymers of vinylidene fluoride with tetrafluoroethylene in an external field

Influence of parameters of molecular mobility on formation of structure in ferroelectric vinylidene fluoride copolymers

Local piezoelectric response, structural and dynamic properties of ferroelectric copolymers of vinylidene fluoride–tetrafluoroethylene

Contact Info

Product

Resources

About