Polymer blends and polymer solutions: a Born-Green-Yvon integral equation treatment

Expressions for the internal energy of mixing and free energy of mixing are derived without requiring the assumption of random mixing. At this stage the treatment describes an incompressible mixture on a lattice; extensions to the case of a compressible mixture are discussed. For the polymer-solvent case comparisons are made with recent simulation results as well as with predictions of other theories describing incompressible lattice solutions. For the case of polymer blends the phase diagram of a mixture exhibiting an upper critical solution temperature in investigated