Main and secondary relaxations of non-polymeric high-Tg glass formers as revealed by dielectric spectroscopy

2020 ◽  
Vol 22 (16) ◽  
pp. 9086-9097
Author(s):  
Thomas Körber ◽  
Felix Krohn ◽  
Christian Neuber ◽  
Hans-Werner Schmidt ◽  
Ernst A. Rössler
Keyword(s):  
Activation Energy ◽  
Dielectric Spectroscopy ◽  
Nitrile Group ◽  
Secondary Relaxations ◽  
Β Relaxation

Manifestation of β-relaxation depends on the position of the polar nitrile group, its distribution of activation energy varies along 19 < E/Tg < 35.

Nafion β-Relaxation Dependence on Temperature and Relative Humidity Studied by Dielectric Spectroscopy

2012 ◽  
Vol 160 (1) ◽  
pp. F43-F48 ◽  
Author(s):  
B. R. Matos ◽  
M. A. Dresch ◽  
E. I. Santiago ◽  
M. Linardi ◽  
D. Z. de Florio ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Dielectric Spectroscopy ◽  
Relaxation Dependence ◽  
Β Relaxation

scholarly journals COMPARATIVE ANALYSIS OF DIELECTRIC AND STRUCTURAL CHARACTERISTICS OF THE SAMPLES BASED ON POLYETHYLENETEREPHTALATE

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Dragana Cerović ◽  
Jablan Dojčilović ◽  
Ivan Petronijević ◽  
Dušan Popović
Keyword(s):  
Comparative Analysis ◽  
Dielectric Spectroscopy ◽  
Structural Characteristics ◽  
Polymeric Materials ◽  
Detailed Examination ◽  
Medical Applications ◽  
Dielectric Parameters ◽  
External Influences ◽  
Woven Structures ◽  
Β Relaxation

Widespread use of polymeric materials from the items for daily use to electrical engineering, electronics and medical applications causes a need for their detailed examination under various external influences. Dielectric spectroscopy allows monitoring changes in the structure of polymers under various external influences. In this paper we analyzed β relaxation recorded in polymer woven structures and meshes based on polyethyleneterephtalate. Based on the results obtained, a comparative analysis of dielectric parameters and structural characteristics of the samples was done.

The state of clay dispersion in maleated polypropylene /organoclay nanocomposites via dielectric spectroscopy measurements

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Yeh Wang ◽  
Syh-W. Huang ◽  
Jiang-Y. Guo
Keyword(s):  
Activation Energy ◽  
Relaxation Time ◽  
Dielectric Spectroscopy ◽  
Interfacial Polarization ◽  
Mechanical Analysis ◽  
The State ◽  
Dispersion Parameters ◽  
Clay Dispersion ◽  
Maleated Polypropylene ◽  
Clay Platelets

AbstractDielectric spectroscopy is a powerful method that allows the study of dynamics of polymers in a wide frequency range. In this work, the state of clay dispersion was related to the dielectric properties of the polymer nanocomposites based on organoclay filled maleated polypropylene (PPgMA). Fully and partially exfoliated samples were prepared through powered sonication and melt blending, respectively. Though two mechanical relaxations were revealed from dynamical mechanical analysis (DMA), only a single high-temperature process resulting from interfacial polarization was observed in broadband dielectric measurements. Dielectric dispersion parameters that appear sensitive to clay loading and degree of exfoliation were identified. The nanomorphology was primarily reflected in the Maxwell-Wagner characteristic relaxation frequency value, fp, where samples with higher degree of exfoliation showed lower relaxation rate. The relaxation time constant, which is the reciprocal of 2πfp, can be correlated with mean distance of clay layer separation in the nanocomposites and therefore provides additional information on exfoliation of clay platelets. A clear evolution of the relaxation activation energy with the degree of clay dispersion was also observed. The experimental results indicated that sonicated samples with fully exfoliated clay platelets yielded the longer relaxation time and the higher activation energy compared to their partially exfoliated counterparts.

Broadband Dielectric Spectroscopy of Polymers with Hidden β Relaxation

2006 ◽  
Vol 39 (15) ◽  
pp. 5043-5051 ◽  
Author(s):  
Gustavo Dominguez-Espinosa ◽  
Ricardo Díaz-Calleja ◽  
Evaristo Riande
Keyword(s):  
Dielectric Spectroscopy ◽  
Broadband Dielectric Spectroscopy ◽  
Β Relaxation
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