SYNTHESIS OF SURFACTANTS BY MICELLAR AUTOCATALYSIS - N,N-DIMETHYLDODECYLAMINE N-OXIDE

The synthesis of N'N-dimethyldodecylamine N-oxide in aqueous solutions by micellar autocatalysis was investigated. Micellar autocatalysis is a novel variation of conventional micellar catalysis in which surfact ant micelles catalyze the reaction by which the surfactant itself is s ynthesized. The lipophilic reactant, dimethyldodecylamine, was initial ly solubilized in micellar solutions of the amine oxide surfactant, re sulting in substantially higher reaction rates. Amine conversions of 9 0-100% were obtained within 2 h at 70 degrees C. The effects of reacta nt concentrations, temperature, and initial surfactant concentration w ere studied. For systems with no surfactant at time zero, the system w as initially an emulsion and reaction rates were low. A sharp increase in the rate was observed when enough surfactant had been produced to form micelles. Activation energy calculations indicate that enhancemen ts of the rate were due primarily to the localized concentration of re actants in the micelle. A simple pseudophase model was used to model r eactions under pseudo-first-order reaction conditions.