Characteristic features of heterophase macromolecular chain reactions involving antioxidants in a non-crystalline polymer matrix

Abstract

The electron drift velocity, the longitudinal diffusion coefficient, the effective ionization coefficient and the limiting field strength for mixtures of SF 6 with CHF 3 and CF 4 have been measured with a pulsed Townsend technique. The overall density-reduced electric field strength, E/N, could be varied between 60 and 520 Td (1 Td = 10 −17 V cm 2 ), while the SF 6 content in the gas mixtures was varied over the range 1-50%. We have found that the electron drift velocity and the density-normalized longitudinal diffusion coefficient vary weakly with the amount of SF 6 in the mixture. In contrast, the effective ionization coefficient shows a strong dependence with the SF 6 content, becoming more electronegative as the amount of SF 6 is increased. The measured limiting field strength for these two mixtures is lower than those for SF 6 -N 2 . To our knowledge, no previous ionization or electron transport data for these mixtures have been published.

Sponge effects in polymers interacting with low-molecular weight compounds

“…However, in the cited works a conclusion about the chain‐sponge carcass‐micellar structure was not formulated. At the present time the properties of the molecular sponge are rather clear 6, 7, 9, 19, 20…”

“…However, the structural model manifesting a polymer as a high‐molecular weight liquid is inadequate for the polymer objects that display a supermolecular skeleton composed of polymer chains packed as a spongy body. The existence of a supermolecular spongy skeleton is thought to be responsible for the invalidity of the homogeneous statistics in explaining, for example, the cold flow, memory effects, and non‐Newton flow of melts2; plasticization anomalies, antiplasticization, and properties of jellies3, 4; sorption,5 the phenomenon of thermodynamic affinity splitting in the single “polymer–liquid nonsolvent” pair,6 important kinetic features of free radical chain reactions,7 and peculiarities of exothermic effects when mixing polymers with their hydrogenized monomers 8, 9…”

Sponge effects in polymers interacting with low‐molecular weight compounds

“…17,18 However, in the cited works a conclusion about the chain-sponge carcass-micellar structure was not formulated. 6,7,9,19,20 6,7,9,19,20 …”

Heterophase mechanisms of thermal oxidation of polymers. New horizons

“…The contradictions caused by the use of the homogeneous reaction model could not fail to cast doubt 16 upon the validity of the mechanisms of inhibited oxidation and `critical' concentrations of antioxidants discussed in the literature. 4, 6 ± 8 Nevertheless, the generally accepted view of the liquid-phase homogeneous structure of a non-crystalline polymeric matrix delayed for a long period the development of an adequate oxidation mechanism, even after the dependence of the reaction rate on the thermomechanical state of the polymeric matrix had been established.…”

“…in the real heterogeneity of the `amorphous' polymer phase. 15,16,28,29 The molecular-chain sponge is actually a system of connected pendula (oscillators), the oscillations of which can become cooperated; this makes the units of macromolecules move apart to form nanopores with different widths.…”