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(GAMMA_(CMC)),equilibrium surface tension at the CMC(gamma_(CMC))cross-sectional area of the adsorbed surfactant molecule(A_(CMC)),efficiency of surface adsorption(pC20),standard free energies of adsorption(DELTA G deg_(ads)),and micellization(DELTA G deg_(CMC))-All investigated di-amidoamines and di-N-oxides were practi cally non-toxic to selected bacteria and yeasts.These compounds are readily biodegradable in the Closed Bottle Test inoculated with activated sludge.Surface and bio logical properties showed that this group of N-oxide-type compounds has high surface activity and fulfills require ments for environmental acceptance.