DIELECTRIC BEHAVIOR OF MIXTURES OF POLYETHYLENE-GLYCOL WITH PROPIONALDEHYDE AND BENZALDEHYDE

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).