The role of topological disorder in the physical chemistry of polymers

Variation of the parameters of inhibited oxidation of polyethylene in the region of phase transition

“…According to the sorption mechanism suggested in [3,8], molecules dissolved in a polymer are mainly concentrated at the sorption centers Z a (sites of distorted short-range order) matching most closely the dissolved molecules (MCHP in our case) in size and shape. Below the melting point of a polymer, crystalline formations arise, preventing migration of macromolecules and their segments, and rearrangement of a sorption center required for formation of a reaction complex requires more energy.…”

“…where the constant k app is equal to the rate constant of the reaction IH + O 2 , k 0 , multiplied by f. The first order of consumption of strong antioxidants in oxidation of polyolefins has been observed repeatedly [1,3].…”

“…As a result, the yield of hydroperoxides decreases from approximately 100% in hydrocarbons to 5320% in hydrocarbon polymers (polyolefins) [1,2], and stable nonuniformities in the macromolecular packing play the role of a second component dissolved in a polymeric substance [3]. In crystalline polymers, crystalline formations appear below the melting points; their content increases with lowering temperature, and in some cases they behave as radical (or, more precisely, free-valence) scavengers.…”

Structural aspects of deformation of amorphous polymers

“…[5][6][7] The structural inhomogeneity of an amorphous polymer has a fluctuative nonequilibrium nature, rather than a phase nature, 8,9 which creates sub stantial experimental difficulties in the studies of the struc ture and mechanism of modifications in amorphous poly mers. The reason is that diffraction methods based on phase contrast of the samples (powder X ray diffrac tion, electron diffraction) are inapplicable.…”

Physical chemistry of topological disorder in polymers: Some remarks on polymer memory

“…Such invariable structures can be only topological ones, that is, based on various knots and interlacements of the polymer chains. 4,5 Some experiments were performed on the sorption of additives with polyethylene and isotactic polypropylene from solutions of these additives in various solvents. In some studies, the substitution of one additive with another, that is, the following process, was observed: 6…”