Micellar-catalyzed alkaline hydrolysis of n-butyl acetate by cetyltrimethylammonium bromide

Abstract

The overall reaction rates of alkaline hydrolysis of n-butyl acetate by aqueous sodium hydroxide solutions, with cetyltrimethylammonium bromide (CTMAB) as a micellar catalyst, were measured in an agitated vessel with a flat interface. The overall reaction rates observed with respect to various liquid compositions could be reasonably explained by the theoretical model, allowing for reactions in the micellar and bulk phases and the distribution of the relevant species between the micellar and bulk phases. This alkaline hydrolysis was accelerated by the solubilization of n-butyl acetate and OH − ions to the micelles, but not by an increase in the reaction rate constant in the micellar phase. The maximum catalytic effect of CTMAB micelles at 298 K occurred at 0.07 kmol m −3 CTMAB and 0.2 kmol m −3 NaOH. The maximum value of the ratio of the overall reaction rates of n-butyl acetate with and without micellar catalyst was about 6. The evaluated apparent reaction rate constants were dependent on the concentration of CTMAB micellar catalyst and the ionic strength of the aqueous solution.