The Influence of Deformation and Chemical Composition on Elementary Free Volumes in Glassy Polymers

Shantarovich, V. P.; Novikov, Yu. A.; Suptel, Z.K.; Олейник, Э. Ф.; Boyce, Mary C.

doi:10.12693/aphyspola.95.659

Cited by 11 publications

(13 citation statements)

References 7 publications

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“…The observed phenomenon may be caused by an increase in the free volume of the polymer glass during its deformation or a change in the size distribution of domains containing the free vol ume. As was found in PALS studies (analysis of positronium annihilation times) [30,31], the total free volume of plastically deformed glassy PMMA increases slightly. In addition, the size distribution of free volume elements changes.…”

Section: α Relaxationsupporting

confidence: 70%

“…The mechanism of the dielectric dispersion anom aly was discussed in [10,[25][26][27]31]. A similar situa tion with dispersion exists in the dynamic mechanical spectrum of PMMA (Fig.…”

Section: Dispersions Of δε and δG In Deformed Pmmamentioning

confidence: 89%

“…Among the results reported in the lit erature, only the data on positronium annihilation (PALS spectroscopy) in the deformed PMMA can be mentioned [30,31]. The bimodal size distribution of free volume elements was found in the indicated papers.…”

Section: Discussionmentioning

confidence: 99%

“…Obviously, this situation is caused by large intermolecular fluctuations of the free volume. This phenomenon is undoubtedly possible in PC, but less probable in PMMA, for which deformation induced changes of the total volume are small [30,31].…”

Section: α Relaxationmentioning

confidence: 99%

“…A certain role may be played here by the appear ance of the bimodal size distribution of free volume elements during PMMA deformation [30,31]. For such a scenario, larger free volume elements should play the decisive role in the initiation of PST.…”

Section: α Relaxationmentioning

confidence: 99%

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Effect of plastic deformation on the character of micro-brownian motions in glassy poly(methyl methacrylate)

et al. 2012

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Glassy PMMA samples are plastically deformed at room temperature in the uniaxial compression regime to residual strains of e res = 25%. Dielectric spectra of the initial and deformed samples are recorded via the method of broadband dielectric spectroscopy in the frequency range f = (5 × 10 -4 ) -10 7 Hz. The results are compared with the dynamic mechanical spectra of samples deformed under the same condi tions. Dielectric and mechanical spectra are noticeably distorted by deformation. As a result, dielectric per mittivity ε' increases, shear modulus G' decreases, and the intensity of dielectric β losses slightly increases, while dielectric and mechanical α losses increase appreciably. In addition, the "anomaly" of total dielectric Δε tot and total mechanical ΔG tot dispersions (Δε tot = ε 0 -ε ∞ ≈ Δε α + Δε β and ΔG tot = G 0 -G ∞ ≈ ΔG α + ΔG β ) occurs, that is, the polymer is transformed from the state with Δε α Δε β and ΔG α < ΔG β into the state with Δε α > Δε β and ΔG α > ΔG β . The described phenomenon is related to a strong gain in α dielectric and mechan ical losses in the deformed material. It is found that α losses increase owing to an anelastic deformation com ponent arising during glass loading. This component is responsible for an increase in the internal energy of the glass during its anelastic deformation. Possible causes of the observed effects are discussed.

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Section: α Relaxationsupporting

confidence: 70%

“…The mechanism of the dielectric dispersion anom aly was discussed in [10,[25][26][27]31]. A similar situa tion with dispersion exists in the dynamic mechanical spectrum of PMMA (Fig.…”

Section: Dispersions Of δε and δG In Deformed Pmmamentioning

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Section: α Relaxationmentioning

confidence: 99%

Section: α Relaxationmentioning

confidence: 99%

See 3 more Smart Citations

Effect of plastic deformation on the character of micro-brownian motions in glassy poly(methyl methacrylate)

et al. 2012

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Simulation of plastic deformation in glassy polymers: Atomistic and mesoscale approaches

Shenogin¹,

Ozisik²

2005

J Polym Sci B Polym Phys

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The mechanism of deformation in glasses is very different from that of crystals, even though their general behavior is very similar. In this study, we investigated the deformation of polycarbonate on the atomistic scale with molecular dynamics and on the continuum scale with a new simulation approach. The results indicated that high atomic/segmental mobility and low local density enabled the formation (nucleation) of highly deformed regions that grew to form plastic defects called plastic shear transformations. A continuum-scale simulation was performed with the concept of plastic shear transformations as the basic region of deformation. The continuum simulations were able to predict the primary and secondary creep behavior. The slope of the secondary creep depended on the interactions between the plastic shear transformations.

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Microporous Polymers for Gas Separation Membranes: Overview and Advances

Buonomenna¹

2019

Handbook of Polymer and Ceramic Nanotechnology

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The Influence of Deformation and Chemical Composition on Elementary Free Volumes in Glassy Polymers

Cited by 11 publications

References 7 publications

Effect of plastic deformation on the character of micro-brownian motions in glassy poly(methyl methacrylate)

Effect of plastic deformation on the character of micro-brownian motions in glassy poly(methyl methacrylate)

Simulation of plastic deformation in glassy polymers: Atomistic and mesoscale approaches

Microporous Polymers for Gas Separation Membranes: Overview and Advances

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