Mechanism of diffusion of monosubstituted benzoic acids through ethylene-vinyl acetate copolymers

The present investigation was undertaken to gain insight into the factors governing diffusion of a series of monosubstituted benzoic acids across ethylene-vinyl acetate copolymers. The interactions between ethylene-vinyl acetate and the benzoic acids were studied using diffusion and partition methods. The diffusion coefficients were found to occupy a narrow range, but the permeability and partition coefficients were found to increase in a non-linear fashion as a function of vinyl acetate content. The results were mathematically consistent with the formation of 1:1 benzoic acid:vinyl acetate complexes.