Аннотация:Five reaction schemes are suggested for the initiated nonbranched-chain
addition of free radicals to the multiple bonds of the unsaturated compounds. The
proposed schemes include the reaction competing with chain propagation reactions
through a reactive free radical. The chain evolution stage in these schemes involves
three or four types of free radicals. One of them is relatively low-reactive and inhibits
the chain process by shortening of the kinetic chain length. Based on the suggested
schemes, nine rate equations (containing one to three parameters to be determined
directly) are deduced using quasi-steady-state treatment. These equations provide
good fits for the nonmonotonic (peaking) dependences of the formation rates of the
molecular products (1:1 adducts) on the concentration of the unsaturated component
in binary systems consisting of a saturated component (hydrocarbon, alcohol, etc.) and an unsaturated component (olefin, allyl alcohol, formaldehyde, or dioxygen). The
unsaturated compound in these systems is both a reactant and an autoinhibitor
generating low-reactive free radicals. A similar kinetic description is applicable to the
nonbranched-chain process of the free-radical hydrogen oxidation, in which the
oxygen with the increase of its concentration begins to act as an oxidation
autoingibitor (or an antioxidant). The energetics of the key radical-molecule reactions
is considered.