The thermal oxidation of ε-caprolactam or N-octylbutyramide in the liquid phase is a chain radical reaction. In the initial stage, the only reaction product is the corresponding amide hydroperoxide, formed from peroxy radicals by a second-order termination reaction. The rates of thermal oxidation reactions initiated with 7,7'-dicumenyl peroxide or 1,1'-azodi(cyclohexanecarbonitrile) and the rates of initiation reactions were measured in the temperature range 80-130 °C. Using the values thus obtained, the ratios of rates of the propagation and termination steps, k2 . k6-1/2, characterizing the oxidizability compounds, were calculated.
