Im. Elanwar et al., DIELECTRIC BEHAVIOR OF MIXTURES OF POLYETHYLENE-GLYCOL WITH PROPIONALDEHYDE AND BENZALDEHYDE, JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY, 11(5), 1995, pp. 373-379
Citations number
14
Categorie Soggetti
Material Science","Metallurgy & Metallurigical Engineering
The dielectric constant epsilon' and dielectric loss epsilon'' of seve
ral mixtures of propionaldehyde-polyethylene glycol (system I) and ben
zaldehyde-polyethylene glycol (system II) have been measured within th
e frequency band 10(5)-10(7) Hz and the temperature range 20-50 degree
s C. The dielectric behaviour is discussed. On the other hand, the die
lectric relaxation time tau, activation energy Delta H-epsilon, and en
torpy change Delta S-epsilon for the dielectric relaxation as well as
activation energy of viscous flow Delta H-nu are calculated for the sa
me temperature range. It is suggested that the observed increase in ta
u values with increasing glycol content is due to an increase in the h
ydrogen bonding in the aggregates or clusters which would be formed be
tween the carbonyl group of the aldehyde and the hydrogen atoms from t
he glycol molecules. In addition, the higher values of tau, Delta H-ep
silon, and Delta S-epsilon in case of system (II) than that in case of
system (I) may be due to the greater volume of the aggregates and the
stronger dipole-dipole forces in system (II) compared with those in s
ystem (I).