Diffusion of alcohols and relaxation in poly(methyl methacrylate): effect of thermal history

The sorption behavior of alkyl alcohols in poly(methyl methacrylate) is analyzed after predetermined annealing treatments of the polymer matrix. Weight uptake, penetration depth and sample dimensions are reported versus time. Dimensionless parameters are used, through which master curves are obtained for both weight uptake and the area perpendicular to the main penetration direction. Contrary to what is observed in polystyrene—n-alkane systems, in the present case either the specific plasticization of the penetrant must be accounted for, or a non-localized swelling model must be used to explain the behavior.