抄録
The temperature dependence of diffusion coefficients of three disperse dyes, p-nitro-aniline, p-amino-azobenzene, and C. I. Disperse Yellow 7, in polyvinylacetate has been investigated by means of a sublimative desorption method over the temperature range 60 to 150°C. Films used for desorption experiments were prepared by mixing the dyes and the polymer using a hot roll heated at 135°C. When the glass transition temperature of this polymer was taken as a reference temperature, the change in the diffusion coefficients with temperature could be expressed by the WLF relation having the constant Cgd2 which was quite close to the universal value of Cg2 (=51.6) in the free volume theory of viscosity. On the other hand, the diffusion parameter Bd obtained from the constant Cgd1 varied from 0.74 to 0.94, and was related linearly to the logarithmic rotational volumes of these dye molecules.
