Quinones (Q) do not affect the liquid-phase oxidation of hydrocarbons and retard the solid-phase oxidation of polymers terminating chains in reactions with alkyl macroradicals. This difference is the result of specific influence of a polymer matrix on the kinetics of free radical reactions. Quinones were found to terminate chains in oxidizing polypropylene containing hydroperoxide groups by the reaction with hydroperoxyl radicals. This is the result of peroxide group's decomposition with hydrogen peroxide production and chain termination in the following reactions: The equilibrium reaction between hydroquinone (QH2) and quinonimine (QI) was evidenced to proceed as a chain reaction with chain propagation in reactions of •QH with QI and HQI• with QH2. Analysis of the reactions of quinone with phenols (ArOH) proved that it can be important as an additional way of chain termination in oxidizing polymers and hydrocarbons at elevated temperatures.
