CHARACTERISTIC FEATURES OF HETEROPHASE MA CROMOLECULAR CHAIN-REACTIONS INVOLVING ANTIOXIDANTS IN A NONCRYSTALLINE POLYMER MATRIX

The principles of kinetic modeling of free-radical chain processes ini tiated in amorphous polymer matrix are presented. The chemical modelli ng was based on the micellar-sponge model for hypermolecular structure , which takes into account the character of different structural zones , differing in size and fluctuational dynamics of micropores forming t hese zones. The influence of antioxidants on chain processes is associ ated with the existence of conjugated reaction chains, localised in va rious zones of chain-sponge micelles. Considerable attention is paid t o the mechanism of autooxidation of polyolefins containing sterically hindered alkyl phenols during the induction period. The induction peri od preceding the oxidation of polymer is regarded as a stage of chain co-oxidation of the antioxidant and the polymer, which is a zero- or f irst-order process with respect to antioxidant (alkyl phenol), dependi ng on its molecular structure.