Synthesis, Surface Properties, and Hydrolysis of Chemodegradable Anionic Surfactants: Diastereomerically Pure cis- and trans-2,5-Disubstituted-1,3-dioxanes
In our continuing systematic studies concerning the synthesis, surface properties, and hydrolysis of chemodegradable, diastereomerically pure surface active 2,5-disubstituted 1,3-dioxane derivatives, two new groups of anionic surfactants, sodium cis- and trans-(2-n-undecyl-1,3-dioxan-5-yl)methyl sulfates and sodium cis- and trans-3-[(2-n-undecyl-1,3-dioxan-5-yl)oxy]propanesulfonates, were synthesized and investigated. Surface properties of these surfactants, i.e., surface excess concentration, Gamma, surface area demand per molecule, A, effectiveness of surface tension reduction, Pi, critical micelle concentration, CMC, and standard free energies of adsorption, DeltaGads0, and of micellization, DeltaGmic0, were determined. It was shown that the trans-isomers, in which the configuration of the polar group is equatorial, are more surface active than the cis-isomers with axial configuration of the polar group at the C-5 carbon atom of the 1,3-dioxane ring. The surfactants under study undergo easy hydrolysis reaction in DCl/D2O solution with cleavage of the 1,3-dioxane ring to nonsurface active intermediates. The trans-isomers are hydrolyzed faster than cis-isomers.
Piasecki
A
Institute of Organic and Polymer Technology, Technical University of Wroclaw, Wroclaw, 50-370, Poland
Sokolowski
A
Burczyk
B
Gancarz
R
Kotlewska
U