Relative reactivities of polymer radicals

The present investigation is concerned with the relationship between P, the reactivity of a radical, and Q that of a monomer in the propagation reaction. At first, P values are calculated from the accumulated data of the rate constants of the propagation reaction. From these results, the relation is shown to be represented by the following equation: where k and a are constants. The P values in the termination reaction (Pt) are also calculated, and the relation between these values and Q values are examined. The results show that the similar relation found in the propagation reaction holds in this step too. By applying the method of Evans and co‐workers, a sufficient explanation for this equation is not obtained, but the analogous equation can be derived. The present authors suggest that the inverse proportion between log P and Q appears to be based on the following different principles: (1) the inverse proportion between the magnitude of localization energy of the radical and that of monomer, and (2) the linear free energy relationship found in organic chemistry.