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

The alkaline hydrolysis of aromatic and normal aliphatic acid esters has been studied at 25 degrees 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(1m) to k(1w) indicate that the alkaline hydrolysis of esters are 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.