Synthesis and Properties of 1,1-bis{[3-(N,N-Dimethylamino)propyl]amido}alkane-di-N-oxides

摘要

A homologous series of new surface-active 1,1-bis{[3-(N,N-dimethylamino)propyl]amido}alkane-di-N-oxides were synthesized in the reaction of an appropriate diethyl 2-alkylmalonate with N,N-dimethylamino-1,3-propanediamine followed by oxidation with aqueous hydrogen peroxide. The adsorption isotherms of their aqueous solutions were measured and evaluated to obtain adsorption parameters: critical micelle concentration (CMC), surface excess concentration (ΓCMC), equilibrium surface tension at the CMC (γCMC), cross-sectional area of the adsorbed surfactant molecule (A CMC), efficiency of surface adsorption (pC20), standard free energies of adsorption (ΔG°ads), and micellization (ΔG°CMC). All investigated di-amidoamines and di-N-oxides were practically non-toxic to selected bacteria and yeasts. These compounds are readily biodegradable in the Closed Bottle Test inoculated with activated sludge. Surface and biological properties showed that this group of N-oxide-type compounds has high surface activity and fulfills requirements for environmental acceptance.