Although gas sorption in glassy polymers is a well‐studied phenomenon, no general microscopical model is developed which is able to describe the gas sorption in a wide temperature range using only characteristics of polymer and gas molecule. In this work, sorption isotherms and desorption kinetics of O2, Ar, and N2 for glassy poly(ethyl methacrylate) have been measured in the temperature range from 160 to 308 K. To describe both the phenomena, the model is developed which postulates that, in the frozen structure of glassy polymer, any cavities between macromolecules are the sorption sites for small molecules. The cavities of small size can expand elastically to accommodate a gas molecule. The sorption sites are considered to be the potential wells and their depths are distributed according to Gaussian law. The concentration of sorption sites, their mean depth and depths dispersion, and the frequency of molecules oscillations in the sorption sites are the only parameters which determine both the gas transport and sorption. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 288–296

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The diffusion of small molecules through amorphous polymers proceeds by the thermally activated jumps whose rate changes from one region to another due to polymer heterogeneity. Little is known at present about the origin of diffusion heterogeneity. The oxidation of triplet nitrene and quenching of phenanthrene phosphorescence have been used to study the movement of molecular oxygen on a nanometer length scale in glassy poly(ethyl methacrylate) and poly(n‐butyl methacrylate) far below the glass transition temperature. It has been found that, as temperature increases, the jump rates in all regions increase by the same factor. This finding points to the equality of the activation energies of oxygen jumps in different regions of the polymers. We conclude that the correlated elastic displacements of polymer chains inside regions about several nanometers in size provide molecules jumps. Due to the large size of these regions, the activation energy of jump does not depend on local polymer structure. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 1097–1104

The reaction C2Hs + 0 2 -C2Hs02 in glassy methanol-d4 and the H-atom abstraction by CH:%, C~H S , and n-C4Hy radicals in C~H S O H + C2DsOH and CDBCH~OH + C~D S O H glassy mixtures have been studied by electron spin resonance. The analysis of the dependence of the reaction rates on the concentration of 0 2 (oxidation) and CzHsOH, CD&HzOH (H-atom abstraction) has shown that the fi law is not conditioned by the existence of regions characterized by different rate constants.

Methyl radical reactions with matrix molecules in glasses C2H50H, (CH20H)z, n-and i-C3H70H, n-and i-C4HsOH, n-and i-CSHIlOH, C~DSOH, and i-C:+D70D, and the reactions of C:2H5, C3H7, C4H9, C :~H I~ with methanol glasses have been studied. Alkyl radicals were produced by photolysis of diphenylamine-alkylhalide-alcohol mixtures using ultraviolet light.In all cases the alkyl radical decay follows the law c = c g exp(-h 4). The 4 law should not be associated with alkyl radical diffusion in a matrix. A method of processing the kinetics of those reactions in which one paramagnetic species changes into another with the total concentration being constant and the electron spin resonance spectra of both species overlapping, is described.