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Dielectric properties of poly(vinyl chloride) in tetrahydrofuran and cyclohexanone
Author(s) -
Salem M. B.,
Oun A. M.,
Omar M. M.
Publication year - 1991
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.4990260403
Subject(s) - cyclohexanone , dielectric , relaxation (psychology) , dipole , tetrahydrofuran , vinyl chloride , solvent , materials science , dielectric loss , analytical chemistry (journal) , chemistry , polymer chemistry , organic chemistry , composite material , polymer , psychology , social psychology , optoelectronics , copolymer , catalysis
Abstract The dielectric absorption and dispersion of poly(vinyl chloride), M M v = 49 000, in THF and in cyclohexanone have been studied over a frequency range of 120 kHz to 11·0 MHz, at temperatures from −22·5 to 35°C, and at concentrations ranging from 4 to 12·0(w/v)% PVC/THF and from 2 to 8·0(w/v)% PVC/cyclohexanone. The viscosities of the two systems have also been measured at temperatures from 20 to 50°C. A single relaxation time was found (β = 0·8–1·0), which indicates that relaxation occurs by segmental rotation. The dielectric and viscous activation energies have been calculated. The dipole moment associated with the relaxation process has also been calculated. The relaxation time, dielectric and viscous activation energies and the dipole moment were found to be dependent on the type of solvent. The dipole moment also showed a molecular weight dependence. The influence of the concentration and temperature on the apparent dipole moment and on the relaxation time is discussed.