To. Gushcha et al., ACOUSTIC RELAXATION OF AQUEOUS-SOLUTIONS OF ETHOXYLATED DIISONONYLPHENOLS, Colloid journal of the Russian Academy of Sciences, 55(5), 1993, pp. 662-668
The results of measurements of the acoustic spectra of aqueous solutio
ns of a series of ethoxylated diisononylphenols in the 5-1200 MHz freq
uency range and 283-333 K temperature range are reported. It was shown
that the fast kinetics of these systems cannot be represented by simp
le monomer- micelle exchange. It was found that several relaxation pro
cesses contribute to the excess absorption of sound in these systems.
One of them, with a relaxation time of 10(-8) sec, is due to rotationa
l isomerism transformations in ethoxy chains. The difference in the en
thalpies of the conformers ranges from 36.8 to 40.2 kJ/mole. The kinet
ic and thermodynamic characteristics of this process were calculated.
The conformational structure of ethoxylated SF in aqueous solutions wa
s discussed.