Kinetics of Phase Separation of Polymer Blends

The phase diagram, especially coexistence curve, can provide us an indispensable information in studying the phase separation kinetics since it gives the stability and the fractional phase volume of the system that are most important factors controlling the phase separation processes. In spite of its importance, there are a very few studies because of experimental difficulties. In this study, we have overcome the difficulties and determined precise coexistence curves of polymer blends.[1–4] Taking advantage of the established coexistence curves, we have studies kinetics of early and late stages of phase separation. As to the early stage, time-evolution of concentration fluctuations in the metastable region has been studied using time-resolved synchrotron small-angle x-ray scattering.[5] For the late stage, the crossover from co-continuous to droplet structure has been investigated, which is primarily governed by the fractional phase volume.[6] Furthermore, using the information obtained here, the morphological structure induced by two-step temperature jump has also been investigated.[7–9] Through these studies, we will demonstrate importance of the coexistence curve in studying phase-separation kinetics.