Diffusion of some dyes in rubbers, liquids, and mixtures

Abstract

The diffusion coefficient of two dyes in various rubbers has been measured at 30 and 50°C. The activation energy does not appear to increase with molecular weight beyond M= 78. The sulphur content and swelling in benzene for each mix are quoted and recommended as standard data for comparison. The diffusion coefficient of 1-benzeneazo 2-naphthol has been measured in various liquids. The product D_η was constant for some mobile liquids tested, but was much greater for the more viscous liquids. The diffusion coefficients in binary and ternary rubber-liquid mixtures (the composition of the latter being measured by a buoyancy method) were (with one exception) in accord with formulae derived from Fujita's free volume theory of diffusion. The solubility of a dye in rubber has been measured and accords with theory.