Dissolution behavior of glassy polymer films founded on reptation theory

A model was developed to simulate the swelling and dissolution behavior of glassy polymer films induced by environmental solvent penetration. The modified Fickian equation was used to predict solvent diffusion behavior inside films, considering the temperature and concentration dependence of diffusion coefficient and moving boundary positions caused by polymer swelling process, followed by dissolution process. The temperature and concentration dependence of diffusion coefficient was obtained using the Vrentas-Duda's hole free volume theory. The polymer dissolution process induced by the disentanglement of polymer chains was predicted, founded on the reptation theory with the polymer and solvent properties. The model confined to the glassy polymers was particularly applied to the polystyrene/ethylbenzene system. As a result, polymer swelling and dissolution behavior was significantly affected by the variation of temperature and polymer molecular weight.