Kinetics of deformation and relaxation in highly oriented polymers

Bronnikov, Sergei; Vettegren, V. I.; Frenkel, S.Ya.

doi:10.1007/bfb0071156

Cited by 18 publications

(10 citation statements)

References 48 publications

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“…From comparison of Eq. (15) with the formula obtained on the basis of the interrelation of the creep and relaxation kinetics of the Young's modulus [9][10][11], it follows that both the relaxation and kinetic approaches lead to a similar description of the temperature-frequency relaxation of the Young's modulus.…”

Section: Resultsmentioning

confidence: 98%

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Temperature and time relaxation of complex Young's modulus of isotropic and oriented polymers

Bronnikov

Vettegren

1999

Mech Compos Mater

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Section: Resultsmentioning

confidence: 98%

“…(11) 4.5 Following Tobol'skii, let us try to describe the frequency dispersion of the real part of the modulus of a highly oriented PMS polymer (~. = 4) in the temperature range from 300 to 525 K, i.e., in the region of an expanded ~-transition overlapped by the a-transition.…”

Section: Resultsmentioning

confidence: 99%

Temperature and time relaxation of complex Young's modulus of isotropic and oriented polymers

Bronnikov

Vettegren

1999

Mech Compos Mater

Self Cite

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“…Let's investigate frequency position temperature dependences. It is known that the Δν T frequency shift during temperature increase from T 1 to T 2 , in other polymers, (Bretzlaff, 1981(Bretzlaff, , 1983Vettegren, 1992Vettegren, , 2009Bronnikov, 1996) can be written as follows:…”

Section: Discussionmentioning

confidence: 99%

Structural Aspects at Phase Transitions in Ferroelectric Copolymers of Vinylidenefluoride and Tetrafluoroethylene

Kochervinskiĭ¹,

Kozlova²,

Бессонова³

et al. 2014

JMSR

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Permittivity and conductivity low-voltage temperature dependences of a ferroelectric copolymer of vinylidenefluoride VDF with tetrafluoroethylene TFE in the ferroelectric to paraelectric phase transition range were investigated. The as received films obtained by crystallization from a solution had the metastable structure shown in particular in coexistence of ferroelectric and paraelectric phases below a Curie point. Temperature dependences of electrical characteristics in the first and second cycles of heating differ. Low glass transition (−40 ºC) facilitate intensive micro-Brownian chains mobility in the amorphous phase at ambient temperatures and above. As per the x-ray and spectroscopic data, the first heating cycle will result in a recrystallization process for molecular structure improvement. Asymmetry of temperature dependence of a dielectric susceptibility in a vicinity of "order-disorder" phase change is found out. For the first time paid attention to the fact that for crystalline polymer ferroelectrics interpretation of the parameters of the temperature dependences of the dielectric susceptibility in the cycle of heating near the phase transition point should take into account the possibility of the premelt processes. First the method of IR spectroscopy shows that the melting of ordered structures, emerging secondary crystallization is accompanied by a change of the basic parameters (frequency position, the integral intensity and half-width) component of the doublet of valence vibrations of С-Н groups. Such structural changes lead to the emergence of "anomalies" on the temperature dependences of conductivity.The phase transition ferroelectric to paraelectric mechanism research is usually done on copolymers P(VDF-TrFE), in which Curie point T c and melting point T m considerably differ (Wang, 1988; Nalva, 1995;Kochervinskii, 1999) more often. In this paper, the order-disorder transition is investigated on copolymer VDF-TFE of composition 71/29 for which both a chain chemical microstructure , and crystallographic parameters (Kochervinskii, 2010) had being studied earlier. It was shown, that in the copolymer isotropic films been crystallized from a low-boiling solvent at room temperature, T c and T m temperate values differ slightly. It was founded out, that the order-disorder transition having the first kind phase transition type. The electric parameter anomalies in the close proximity to a ferroelectric-paraelectric transition are depends on www.ccsenet.org/jmsr

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“…3, несимметрична: на ее длинноволновом крыле наблюдается слабо выраженный дополнительный максимум около ~ 908 см -1 . Несимметричная форма суммарной полосы обусловлена тем, что в пленке существуют деформированные (растянутые) на различную ве-личину участки полимерных молекул [6][7][8][9][10][11][12][13][14][15][16][17][18]. По этой причине частоты их колебаний смещены в сторону низких частот на различную вели-чину (см.…”

Section: 3)unclassified

Долговечность Полимерных Композитов

Башкарев¹,

Веттегрень²,

Суслов³

2016

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Kinetics of deformation and relaxation in highly oriented polymers

Cited by 18 publications

References 48 publications

Temperature and time relaxation of complex Young's modulus of isotropic and oriented polymers

Temperature and time relaxation of complex Young's modulus of isotropic and oriented polymers

Structural Aspects at Phase Transitions in Ferroelectric Copolymers of Vinylidenefluoride and Tetrafluoroethylene

Долговечность Полимерных Композитов

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