Phase behaviour and separation kinetics of polymer blends

The liquid-liquid phase separation kinetics and phase behaviour of hydrogenated polyethylene and deuterated polypropylene blends have been systematically studied by optical microscope. Phase diagram was constructed from the phase transition temperature. The hydrogenated polyethylene/deuterated polypropylene blend exhibits upper critical solution temperature in the melt. The time evolution of the characteristics morphology for liquid-liquid phase separation is determined for the hydrogenated polyethylene/deuterated polypropylene blend at various compositions and following a quench from initial homogenous melts at higher temperature to various lower temperatures. Liquid-liquid phase separation kinetics follows nucleation and growth mechanism. The experimental results from optical microscope measurement at various conditions are all consistent with the nucleation and growth mechanism.