Thermodynamics of Polymer Mixing
One of the main tasks of the investigation in the field of thermodynamics of mixing is to find the conditions of mixing and ranges of mutual solubility of different polymers depending on their chemical nature and molecular mass. In many cases, to estimate miscibility of two polymers, there were used approximations of the theory of regular solutions. The main characteristics of polymer blends is thermodynamic compatibility or incompatibility of the components which is governed by the phase diagram of the system. To characterize the stability of the systems consisting of two polymers of high molecular mass, I. C. Sanchez has developed the theory based on the model of compressible lattice. The thermodynamic stability in the interphase increases due to conformational changes. Depending on the surface nature and interaction energy, the effects under consideration can be manifested in various ways. Many works were dedicated to the determination of miscibility from the data on heat effects of mixing.