Heterophase mechanisms of thermal oxidation of polymers. New horizons

Abstract

Based on the results of kinetic analysis of numerous experimental data, advantages of heterogeneous and heterophase mechanisms of autooxidation of non-crystalline polymers over homogeneous liquid-phase mechanisms are demonstrated. The supermolecular organisation of polymer chains according to the pattern of spongy micelles incorporating non-uniform porous areas is chosen as the model structure. It is established that, depending on the physical state of the polymer, the oxidation kinetics correspond either to a mechanism in which reaction chains are distributed over non-uniform nanophases or to a mechanism in which they are mainly located in one nanophase. The kinetic equations obtained for the macroscopic stages of oxidation take into account the dependence of the chemical reactivity of reactants on the thermomechanical mobility of the molecular sponge. It is demonstrated that the fine structure of molecular spongy micelles plays a crucial role in the chemical physics of polymers. The bibliography includes 94 references.