Determination of the diffusion coefficients of dyes in polymer media by the absorption method with a high spatial resolution

The coefficients of diffusion of coumarin 7 in polyurethaneacrylate are determined by a new optical absorption method based on measurement of the absorption gradient at the boundary between the colored and colorless sections of the polymer. The dependence of the diffusion coefficient on concentration is found. The obtained values for the diffusion coefficients of the dye in an elastic matrix allow one to consider that the gradient optical elements in elastomers will be characterized by a relatively large lifetime.