Interdiffusion dynamics at the interface between two polystyrenes with different molecular weight probed by a rheological tool

Interdiffusion between two molten polystyrenes is studied under small amplitude oscillatory shear (SAOS). Our rheological technique exploits differences in molecular weights and thus in viscosity, to investigate interdiffusion dynamics. The torque is measured during radial interdiffusion in a concentric binary sample, at constant temperature and frequency. We have previously confirmed that our rheological technique can be used to characterize solvent diffusion in molten polymers. Our results confirm that the interdiffusion rate is significantly increased due to oscillatory motion.