Upper critical solution temperature behavior in poly(vinylidene fluoride)/poly(methyl methacrylate) blends

Abstract

We investigated the morphological development in poly(vinylidene fluoride)/poly(methyl methacrylate) blends during the isothermal annealing below melting temperature. At shallow quench depth from the melting point, normal spherulite growth was observed. At deep quench depth, liquid-liquid phase separation took place, resulting in a modulated structure characteristic to spinodal decomposition. There exists a defined boundary between 舠the shallow舡 and 舠the deep舡 regions in phase diagram. This suggests the existence of upper critical solution temperature (UCST). The UCST behavior was confirmed by dynamic mechanical analysis and Fourier transform infrared spectroscopy. © 1987 The Society of Polymer Science, Japan.