Reactions of $\mathrm{R}\dot{\mathrm{O}}$, $\mathrm{R}\dot{\mathrm{S}}$, and $\mathrm{R}\dot{\mathrm{O}_2}$ Radicals with Phosphites and Phosphines

The review deals with studies designed to elucidate the detailed mechanism and quantitative relations in the kinetics of the reactions of $\mathrm{R}\dot{\mathrm{O}}$, $\mathrm{R}\dot{\mathrm{S}}$, and $\mathrm{R}\dot{\mathrm{O}_2}$ radicals with phosphites and phosphines. It is shown how the isotope tracer method has been used to prove the irreversible formation of the phosphoranyl radical — the primary intermediate in these radical reactions. The results of the study of the competition between the addition of $\mathrm{R}\dot{\mathrm{O}}$ and $\mathrm{R}\dot{\mathrm{S}}$ radicals to phosphites and phosphines on the one hand and their other reaction pathways (abstraction of a hydrogen atom from hydrocarbons, addition to a double bond, and monomolecular decomposition) on the other have been analysed. The last section discusses the mechanism of the inhibiting effect of aromatic phosphites in the thermo-oxidative degradation of polyolefins within the framework of the hypothesis that they terminate kinetic oxidation chains by radical exchange.

The bibliography includes 49 references.