Influence of molecular weight on dynamic crossover temperature in linear polymers

S. Pawlus; K. Kunal; L. Hong; A. P. Sokolov

doi:10.1016/j.polymer.2008.04.040

Influence of molecular weight on dynamic crossover temperature in linear polymers

S. Pawlus, K. Kunal, L. Hong, A. P. Sokolov

Research output: Contribution to journal › Article › peer-review

26 Scopus citations

Abstract

Dielectric and light scattering spectra of two linear polymers, polyisoprene (PIP) and polystyrene (PS), were analyzed in broad temperature and frequency range above the glass transition temperature, T_g. The crossover temperature, T_C, was estimated using two approaches: (i) derivative analysis of relaxation times proposed by Stickel and (ii) Mode-Coupling Theory approach. Both estimates provide consistent values. T_C varies with molecular weight (MW) in both polymers, while the ratio T_C/T_g changes significantly with MW in PS only. It appears that the segmental relaxation time at T_C has value τ(T_C) ∼ 10^-7 s for both polymers independent of MW and similar to the value reported for many non-polymeric glass-forming systems. No sign of the dynamic crossover has been observed in the chain relaxation around T_C of the segmental dynamics.

Original language	English
Pages (from-to)	2918-2923
Number of pages	6
Journal	Polymer
Volume	49
Issue number	12
DOIs	https://doi.org/10.1016/j.polymer.2008.04.040
State	Published - Jun 10 2008
Externally published	Yes

Keywords

Dynamic crossover
Glass transition
Polymers

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10.1016/j.polymer.2008.04.040

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title = "Influence of molecular weight on dynamic crossover temperature in linear polymers",

abstract = "Dielectric and light scattering spectra of two linear polymers, polyisoprene (PIP) and polystyrene (PS), were analyzed in broad temperature and frequency range above the glass transition temperature, Tg. The crossover temperature, TC, was estimated using two approaches: (i) derivative analysis of relaxation times proposed by Stickel and (ii) Mode-Coupling Theory approach. Both estimates provide consistent values. TC varies with molecular weight (MW) in both polymers, while the ratio TC/Tg changes significantly with MW in PS only. It appears that the segmental relaxation time at TC has value τ(TC) ∼ 10-7 s for both polymers independent of MW and similar to the value reported for many non-polymeric glass-forming systems. No sign of the dynamic crossover has been observed in the chain relaxation around TC of the segmental dynamics.",

keywords = "Dynamic crossover, Glass transition, Polymers",

author = "S. Pawlus and K. Kunal and L. Hong and Sokolov, {A. P.}",

year = "2008",

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day = "10",

doi = "10.1016/j.polymer.2008.04.040",

language = "English",

volume = "49",

pages = "2918--2923",

journal = "Polymer",

issn = "0032-3861",

publisher = "Elsevier",

number = "12",

}

TY - JOUR

T1 - Influence of molecular weight on dynamic crossover temperature in linear polymers

AU - Pawlus, S.

AU - Kunal, K.

AU - Hong, L.

AU - Sokolov, A. P.

PY - 2008/6/10

Y1 - 2008/6/10

N2 - Dielectric and light scattering spectra of two linear polymers, polyisoprene (PIP) and polystyrene (PS), were analyzed in broad temperature and frequency range above the glass transition temperature, Tg. The crossover temperature, TC, was estimated using two approaches: (i) derivative analysis of relaxation times proposed by Stickel and (ii) Mode-Coupling Theory approach. Both estimates provide consistent values. TC varies with molecular weight (MW) in both polymers, while the ratio TC/Tg changes significantly with MW in PS only. It appears that the segmental relaxation time at TC has value τ(TC) ∼ 10-7 s for both polymers independent of MW and similar to the value reported for many non-polymeric glass-forming systems. No sign of the dynamic crossover has been observed in the chain relaxation around TC of the segmental dynamics.

AB - Dielectric and light scattering spectra of two linear polymers, polyisoprene (PIP) and polystyrene (PS), were analyzed in broad temperature and frequency range above the glass transition temperature, Tg. The crossover temperature, TC, was estimated using two approaches: (i) derivative analysis of relaxation times proposed by Stickel and (ii) Mode-Coupling Theory approach. Both estimates provide consistent values. TC varies with molecular weight (MW) in both polymers, while the ratio TC/Tg changes significantly with MW in PS only. It appears that the segmental relaxation time at TC has value τ(TC) ∼ 10-7 s for both polymers independent of MW and similar to the value reported for many non-polymeric glass-forming systems. No sign of the dynamic crossover has been observed in the chain relaxation around TC of the segmental dynamics.

KW - Dynamic crossover

KW - Glass transition

KW - Polymers

UR - http://www.scopus.com/inward/record.url?scp=44549085493&partnerID=8YFLogxK

U2 - 10.1016/j.polymer.2008.04.040

DO - 10.1016/j.polymer.2008.04.040

M3 - Article

AN - SCOPUS:44549085493

SN - 0032-3861

VL - 49

SP - 2918

EP - 2923

JO - Polymer

JF - Polymer

IS - 12

ER -

Influence of molecular weight on dynamic crossover temperature in linear polymers

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