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Detection of secondary relaxation in polyacetal, polycarbonate and polyether–sulfone by ultrasonic and dielectric methods
Author(s) -
Aziz A. W.,
AbElNour K. N.
Publication year - 1986
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1986.070310725
Subject(s) - polycarbonate , materials science , dielectric , relaxation (psychology) , sulfone , polymer , permittivity , ultrasonic sensor , loss factor , composite material , dielectric loss , polymer chemistry , range (aeronautics) , optoelectronics , acoustics , social psychology , physics , psychology
The ultrasonic pulse echo technique in the range of frequencies between 1 and 5.7 MHz and temperatures between 170 and 360 K is used to detect the secondary relaxations in polyacetal, polycarbonate, and polyether–sulfone. The activation energies and the relaxation frequencies were calculated and they were found to be comparable in value. The dielectric permittivity ε′ and loss factor tan δ for such polymers were also studied over a frequency range from 10 2 and 10 5 Hz and temperatures between 30 and 80°C. At higher temperatures, the polymers possess better dielectric properties.