The Cooxidation of Hydrocarbons in the Liquid Phase. V. Determination of the Reactivity Ratios

The cooxidations of cumene (C) and tetralin (T) and of styrene (S) and tetralin were studied in the presence of azobisisobutyronitrile; the reactivity ratios, r, were obtained as rC=0.21 and rT=5.0 for the cumene-tetralin system at 80°C and as rS=2.7 and rT=0.49 for the styrene-tetralin system at 70°C. A new method for the determination of r values from the rates of cooxidation has been developed. The merits and demerits of several methods for the determination of r values are discussed. In cases where a large curvature, preferably a rate minimum, is obtained by plotting the rates against the reactant compositions, the determination from the rates of cooxidation may be most suitable. In other cases, the use of the copolymerization equation may be preferable by product analyses. The hydroperoxide method may be valid for some systems.