OXIDATION-KINETICS OF P-AMINODIPHENYLAMINE WITH PEROXYDISULFATE

The kinetics of oxidation of p-aminodiphenylamine with the peroxydisul phate ion were investigated spectrophotometrically. The oxidation was accompanied by the appearance of a wine-red colour, which changed to b ecome colourless. ne reaction rate was measured by the stopped-flow te chnique with a UV spectrophotometer. The reactions proceeded with seco nd-order kinetics, first-order for each individual reactant. Cationic micelles (cetyltrimethyl ammonium bromide) caused an enhancement in th e reaction rate followed by inhibition at higher concentrations. Anion ic micelles (sodium dodecyl sulphate), on the other hand, had a slight ly retarding effect. The effects of radical scavenger, pH and ionic st rength on the fast oxidation mte were examined. A mechanism consistent with the observations is discussed.