Liquid-liquid equilibria of binary polymer blends: molecular thermodynamic approach

We extended and simplified the modified double‐lattice model to binary polymer blend systems. The model has two model parameters, Cβ and Cγ. Those are not adjustable parameters but universal functions. In comparison with Ryu et al.'s simulation data for symmetric polymer blend with various chain lengths (r1 = r2 = 8, 20, 50, 100), Cγ is determined. Our results show that Cβ is negligible for symmetric polymer blend systems. The proposed model describes very well phase behaviors of weakly interacting polymer blend systems.