Abstract
We studied the solvent-induced stresses and solvent-induced surface pattern in glassy polymers. The solvent transport in glassy polymers is described by Case I, Case II, and anomalous transport. Case I transport is driven by concentration gradient, and Case II transport is due to stress relaxation. Anomalous transport is the mixture of Case I and Case II. Concentration profile for both two-side absorption of anomalous transport and one-side desorption of Case I transport were derived. Two initial conditions for one-side desorption in PMMA were analyzed. The activation energy of diffusion coefficient is found to be lower in one-side desorption than that in two-side absorption. The elastic models of stress distributions and longitudinal displacement arising from the mass transport were built up and were analyzed for PMMA. From the displacement data, the partial molar volume of methanol in PMMA during the transport process was determined. Surface pattern occurs when a polymer slab is under a large enough compressive stresses. The stresses arising from the mass transport are found to be compressive near the surfaces for two-side resorption in PC. A method combining the solvent-induced stresses and the mechanical instability of a slab under compression is developed to analyze the solvent-induced surface pattern on PC. The calculated pattern wavelengths are at the same order and have the same trend with that of experimental results.