Diffusion of low-molecular-mass substances in the region of polymer glass transition

The temperature dependences of the diffusion coefficients of low-molecular- mass substances in polymers of various chemical natures were studied. The d ata obtained were used to analyze the parameters of mass transfer in the re gion of polymer glass transition. The results were interpreted in terms of the theories of activated diffusion and free volume. It was shown that the diffusion coefficients of the specific low-molecular-mass substances in the glass transition regions of different polymers were almost equal.