THE EFFECT OF CATIONIC, ANIONIC, AND NONIONIC SURFACTANT MICELLES ON THE ALKALINE HYDROLYSIS OF ESTERS

ABSTRACT

The alkaline hydrolysis of aromatic and normal aliphatic acid esters has been studied at 25°C in micellar solutions of surfactants (DTAB, TTAB, CTAB, SDS, Brij 35 and Triton X—100) with UV spectrophotometry and the method of thermokinetics in this paper. The rate constants of the alkaline hydrolysis of esters in micellar pseudophase, k_1m and K_2m have been calculated, respectively. The ratios of k_2m to k_2w or k_1w to k_1w indicate that the alkaline hydrolysis of esters arc inhibited by all of the surfactants investigated. It was supposed that such inhibition is mostly in relation to the micropolarity of micellar surface. The critical micellar concentrations of the corresponding systems have also been measured with the conductivity method and UV spectrophometry in this paper.