Complexation Extraction of p-Aminophenol with Di(2-Ethylhexyl) Phosphoric Acid in Diffrent Diluent

Di(2-ethylhexyl)phosphoric acid was used as the extraction agent for the extraction of p-aminophenol in 2-octanol and kerosene.Equilibrium data for active and inactive diluents were obtained at various di(2-ethylhexyl)phosphoric acid concentrations.Di(2-ethylhexyl)phosphoric acid extracted both neutral and positive forms of p-aimnophenol.The initial pH values (pH 2—11) have a large effect on D values,and the maximum distribution coefficient occurred between pK_ a1 and pK_ a2.The effects of diluents on D come true by physical extraction. At the same concentration, the extractabilities of di(2-ethylhexyl)phosphoric increased as the polarity of diluents rised.Fourier transform infrared spectrophotometer (FTIR) study indicates that there exist the ion-association and ion-exchange reactions in the extraction process.