γ→β Phase transformation induced in poly(vinylidene fluoride) by stretching

Imamura, Rikizo; Silva, A. B.; Grégório, Rinaldo

doi:10.1002/app.28851

Cited by 73 publications

(52 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The existing literature did not show a melting temperature for the different phases, but showed a temperature range. The expected melting temperatures of the α and β phases of PVDF are similar and range from 167-172ºC [41][42][43] so DSC is not used to distinguish these two phases, but to calculate the crystalline percentage of the film [30]. On the other hand, PVDF crystallized in the γ phase has a melting temperature of about 179-180ºC when it is obtained by crystallization from the melt [41], and around 189-190 ºC [41,42] when obtained from the α→γ transformation in the solid state.…”

Section: Qualificationmentioning

confidence: 94%

Crystalline polymorphism in poly(vinylidenefluoride) membranes

Cui

Hassankiadeh

Zhuang

et al. 2015

Progress in Polymer Science

323

242

View full text Add to dashboard Cite

Section: Qualificationmentioning

confidence: 94%

Crystalline polymorphism in poly(vinylidenefluoride) membranes

Cui

Hassankiadeh

Zhuang

et al. 2015

Progress in Polymer Science

323

242

View full text Add to dashboard Cite

“…It is well known that changes of the processing conditions and preparation of PVDF film samples lead to significant changes of their morphology [1][2][3][4][5][6][7]. Depending on these conditions, three PVDF conformations: α-, β-, and γ-phases can be observed [7,8].…”

Section: Introductionmentioning

confidence: 99%

Influence of the processing method on the properties of a PVDF film

2011

View full text Add to dashboard Cite

The main electrophysical properties of polyvinylidene fluoride (PVDF) films produced by two technologies: the solution casting method and the method of hot pressing from the melt are investigated. To analyze the PVDF films, methods of dielectric spectroscopy (DS), IR spectroscopy, TGA/DSC analysis, and x-ray diffraction (XRD) are used. It is demonstrated that the IR spectra of both PVDF films change weakly in comparison with the virgin PVDF film. The absorption bands characteristic for α-, β-, and γ-phases are observed for the virgin and both types of PVDF films. This testifies to the fact that the molecular structure of film samples is practically independent of their processing method. The only difference is that the new absorption band at 1723 cm -1 arises in the IR spectra of the films produced by the method of hot pressing from the melt. The TGA/DSC analysis demonstrates that the beginning melting temperature, melting temperature, beginning decomposition temperature, and decomposition temperature for the film samples produced by the method of hot pressing from the melt decrease by 8, 2, 10, and 12°C, respectively, compared to the film samples produced by the solution casting method.

show abstract

“…FTIR spectra also indicated that the PVDF nanofibers contained both crystalline and amorphous phases. [29] The characteristic peaks at 840 and 1274 cm −1 were assigned to the absorption bands of β crystal phase. Weak bands at 761, 795, and 976 cm −1 corresponded to α crystal phase.…”

Section: Characterizationsmentioning

confidence: 99%

Mechanical Energy‐to‐Electricity Conversion of Electron/Hole‐Transfer Agent‐Doped Poly(Vinylidene Fluoride) Nanofiber Webs

Shao

Fang

Wang

et al. 2017

Macro Materials & Eng

View full text Add to dashboard Cite

Electrospun poly(vinylidene fluoride) (PVDF) nanofibers have shown novel property to convert kinetic energy into electricity. However, most of the PVDF nanofiber energy devices are based on pure PVDF. In this paper, the effect of small molecule doping on PVDF nanofiber diameter, β phase content, and mechanical‐to‐electrical energy conversion property is reported. Two chemicals, tri‐p‐tolylamine (TTA) and 2‐(4‐tert‐butylphenyl)‐5‐(4‐biphenylyl)‐1,3,4‐oxadiazole (Butyl‐PBD) which have electron‐ and hole‐transfer features, respectively, are chosen as dopants. When the nanofibers contain 0.5% TTA or 1% Butyl‐PBD, they show high β phase content and electric outputs. By combining a layer of nanofiber web which contained TTA with a layer of nanofiber web containing Butyl‐PBD, the voltage output is changed to 3.1 V, increasing by ≈100% when compared with the single layer nanofiber device of the same thickness. In addition, asymmetric electric outputs are observed in the two layer energy device. These novel features are probably attributed to the high internal polarity across the nanofiber web.

show abstract

γ→β Phase transformation induced in poly(vinylidene fluoride) by stretching

Cited by 73 publications

References 23 publications

Crystalline polymorphism in poly(vinylidenefluoride) membranes

Crystalline polymorphism in poly(vinylidenefluoride) membranes

Influence of the processing method on the properties of a PVDF film

Mechanical Energy‐to‐Electricity Conversion of Electron/Hole‐Transfer Agent‐Doped Poly(Vinylidene Fluoride) Nanofiber Webs

Contact Info

Product

Resources

About