Инд. авторы:	Oleinik E.F., Chmutin I.A., Ryvkina N.G., Zhorin V.A., Rudnev S.N.
Заглавие:	Effect of plastic deformation on the character of micro-brownian motions in glassy poly(methyl methacrylate)
Библ. ссылка:	Oleinik E.F., Chmutin I.A., Ryvkina N.G., Zhorin V.A., Rudnev S.N. Effect of plastic deformation on the character of micro-brownian motions in glassy poly(methyl methacrylate) // Polymer Science - Series A. - 2012. - Vol.54. - Iss. 6. - P.465-475. - ISSN 0965-545X.
Внешние системы:	DOI: 10.1134/S0965545X12060053; SCOPUS: 2-s2.0-84863715198;
Реферат:	eng: 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 e' 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 Δetot and total mechanical ΔG tot dispersions (Δε tot = ε 0 - ε ∞ ≈ Δε α + Δeβ and ΔG tot = G 0 - G ∞ ≈ ΔG a + ΔG β) occurs, that is, the polymer is transformed from the state with Δε α Δεβ and ΔG α < ΔGβ into the state with Δε α > Δε β and ΔGa > ΔG β. The described phenomenon is related to a strong gain in a dielectric and mechan- ical losses in the deformed material. It is found that a 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. © Pleiades Publishing, Ltd., 2012.
Ключевые слова:	Loading; Glass; Esters; Deformation; Brownian movement; Uni-axial compression; Room temperature; Residual strains; Micro-brownian motion; Internal energies; Frequency ranges; Dynamic mechanical; Dielectric spectra; Deformed samples; Broad-band dielectric spectroscopy; Anelastic deformation;
Издано:	2012
Физ. характеристика:	с.465-475