Transitions and Relaxations in Poly(trifluoroethylene)

Yagi, Toshiharu

doi:10.1295/polymj.11.711

Cited by 18 publications

(9 citation statements)

References 21 publications

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“…Yagi observed that anomalous linkages such as head-to-head or tailto-tail are contained considerably in PTrFE. 4 These linkages possibly yield defects in crystals, and annealing may decrease the disorder or irregular conformations around this type of defects. The f3' relaxation is likely related to this type of defect.…”

Section: Resultsmentioning

confidence: 99%

“…Yagi did not find the resolved {3' relaxation so that he ascribed the f3 relaxation partly to local molecular motions around this type of defect in crystals. 4 As considered in some crystalline polymers, row vacancy defects at chain ends are also present in crystals. 5 The activation energy for the /Jc relaxation in PTrFE was similar to those for the chain end defects in crystals of polyethylene and PCTFE.…”

Section: Resultsmentioning

confidence: 99%

“…Yagi observed the same behavior of the f3 relaxation in mechanical measurements and ascribed the f3 relaxation partly to local molecular motions around defects of anomalous linkages of headto-head and tail-to-tail. 4 Furukawa et a/. 6 studied the dielectric properties of PTrFE and vinylidene fluoride-trifluoroethylene (VDFTrFE) copolymer with entire range of comonomer content.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Absorbed Benzene on Relaxation Behavior of Polytrifluoroethylene

Murata

1988

Polym J

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ABSTRACT:Relaxation behavior in polytrifluoroethylene (PTrFE) with varied crystallinity and swollen with benzene was investigated by mechanical and dielectric measurements. PTrFE showed the ct, /3, and /3' relaxation in decreasing order of temperature. The f3 relaxation observed around -20°C at I 00 Hz was considered to consist of two components assigned to the amorphous and crystalline regions. The /3' relaxation found in a lower temperature region below -50°C was related to molecular motions around the defects of anomalous linkages such as head-to-head and tail-to-tail. In swollen PTrFE, the ct relaxation due to the micro-Brownian motions of main chains shifted from 50°C to -l0-0°C in mechanical measurements. The f3 relaxation for swollen samples decreased in intensity or vanished. This was interpreted by considering that the component assigned to the amorphous regions did not occur or was concealed by the ct relaxation shifted to lower temperature. Relaxation behavior of the component assigned to the crystalline regions was revealed in swollen samples and related to reorientation of chains adjacent to the row vacancy defects at chain end.KEY WORDS Polytrifluoroethylene / Swelling / Dielectric Relaxation / Overlapped Relaxation / Component / Defects / Chain End / Anormalous Linkage / In polytrifluoroethylene (PTrFE) two relaxations, designated as a and /3 in decreasing order of temperature, were found by some authors. 1 -4 The a relaxation was attributed to the micro-Brownian motions of the main chains. The f3 relaxation shifted to low temperature and increased in magnitude with increasing crystallinity. 1 • 2 • 4 The similar shift to the f3 relaxation was observed for the y relaxation of polychlorotrifluoroethylene (PCTFE) and ascribed to overlapping of two components, Ya and Ye, in the amorphous and crystalline regions, respectively. 5 Thus the /3 relaxation of PTrFE was considered to consist of two components in the amorphous and crystalline regions. 1 • 2 It was inferred that the crystalline relaxation was likely related to row vacancy defects at the chain end in crystals as considered in the Ye relaxation of PCTFE. Yagi observed the same behavior of the f3 relaxation in mechanical measurements and ascribed the f3 relaxation partly to local molecular motions around defects of anomalous linkages of headto-head and tail-to-tail. 4 Furukawa et a/. 6 studied the dielectric properties of PTrFE and vinylidene fluoride-trifluoroethylene (VDFTrFE) copolymer with entire range of comonomer content. They ascribed the relaxation found at -20°c and l kHz in the copolymers to the rotational molecular motions of the all trans segments to gauche in the amorphous regions similar to those of the ferroelectric relaxation in crystalline regions. In contrast to this assignment, it was considered in the mechanical study 1 that the relaxation for copc,.>lymers with 48 to 71 mol% TrFE was related to the micro-Brownian motions of VDF rich sequences and that the 251

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Effects of Absorbed Benzene on Relaxation Behavior of Polytrifluoroethylene

Murata

1988

Polym J

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“…With the addition of over 17 mol% TrFE units via direct polymerization process, P(VDF‐ co ‐TrFE) chains prefer all ‐trans conformation and unit cell of β phase directly 17. Yagi et al18–20 have investigated the molecule conformation and crystalline form of P(VDF‐ co ‐TrFE) over the entire range of composition by means of X‐ray diffraction (XRD) and infrared spectroscopy. Pure PTrFE was found to be a stereo‐irregular containing ∼50% of inversely added monomeric units and adopt a 3/1‐helical conformation.…”

Section: Introductionmentioning

confidence: 99%

“…Pure PTrFE was found to be a stereo‐irregular containing ∼50% of inversely added monomeric units and adopt a 3/1‐helical conformation. The addition of less than about 85 mol % VDF could result in trans or trans ‐like conformation while higher VDF concentrations would yield TGTG′ conformation in the copolymers 18–21. Mechanical stretching process, external electric‐field polarization, and thermal treatment have been reported to exhibit significant influence on the final crystalline phases of these polymers as well 22–26…”

Section: Introductionmentioning

confidence: 99%

Crystal phase of poly(vinylidene fluoride‐co‐trifluoroethylene) synthesized via hydrogenation of poly(vinylidene fluoride‐co‐chlorotrifluoroethylene)

Zhang

Xia

Zhu

et al. 2012

J of Applied Polymer Sci

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Trifluoroethylene addition and thermal treatment induced crystal phase transition in a series of poly(vinylidene fluoride-cotrifluoroethylene) [P(VDF-co-TrFE)] containing varied TrFE molar ratio (6,9,12, and 20 mol %) prepared from the hydrogenation of poly(vinylidene fluoride-co-chlorotrifluoroethylene have been investigated by means of Fourier transform infrared spectral (FTIR), Xray diffraction (XRD), and differential scanning calorimetry (DSC) analyses. The comprehensive applications of the three techniques could distinguish a, b and c phase of P(VDF-co-TrFE) very well. The multipeak fitting technique of DSC is successfully applied to calculate the percentage of different phases in the samples, which allows us to investigate the phase transition process of P(VDF-co-TrFE) precisely. It is found that the crystal phase of P(VDF-co-TrFE) films is turned from a þ c phase (6 mol % TrFE) to a þ c þ b phase (9 and 12 mol % TrFE) to b phase (20 mol % TrFE) at high temperature, and from a þ c phase (6 mol % TrFE) to c þ b phase (9 mol % TrFE) to b phase (>12 mol % TrFE) at low fabricated temperature. Both the fabrication conditions and TrFE addition are responsible for the crystal phase transition of the hydrogenised P(VDF-co-TrFE).

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Ferroelectric order and phase transition in polytrifluoroethylene

Oka

Koizumi

Murata

1986

J Polym Sci B Polym Phys

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SynopsisPolarization-reversal currents and x-ray profiles under a high dc field were measured on polytrifluoroethylene (PTrFE) samples prepared by melt crystallization at different cooling rates. The results for PTrFE were found to be analogous to those for copolymers of vinylidene fluoride and trifluoroethylene [p(VDF/TrFE)] with low VDF content. Slowcooled and quenched samples showed different x-ray profdes but the same IR spectra. For the slowcooled samples, a polarization reversal was clearly obse~ed as a peak in polarization current, offering evidence for ferroelectric order in F'TrFE. The ferroelectric behavior was found to be unlike that of typical ferroelectric polymers. There are two processes in a polarization reversal, i.e., partial depolarization and polarization reversal, accompanied by crystalline phase transitions.It is noted that no ferroelectric order was observed for the quenched sample which, however, becomes pyroelectric by poling as revealed by our previous studies. We speculate on possible crystal structures of PTrFE based on the published structure models and the present results. The relation between the ferroelectricity and the previously reported pyroelectricity is also discussed.'Present address:

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Transitions and Relaxations in Poly(trifluoroethylene)

Cited by 18 publications

References 21 publications

Effects of Absorbed Benzene on Relaxation Behavior of Polytrifluoroethylene

Effects of Absorbed Benzene on Relaxation Behavior of Polytrifluoroethylene

Crystal phase of poly(vinylidene fluoride‐co‐trifluoroethylene) synthesized via hydrogenation of poly(vinylidene fluoride‐co‐chlorotrifluoroethylene)

Ferroelectric order and phase transition in polytrifluoroethylene

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