Polymer–polymer miscibility: generalized double lattice model

We generalize the modified double lattice model (mDLM) to investigate the miscibility of polymer blend systems. We re-define model parameters, Cβ and Cγ, as functions of chain length of polymer and interaction energy. Cβ corrects the degree of asymmetry between two molecules. C γ reduces the mathematical defects originated from the truncation of higher order interaction energy terms. We correlate Cβ and Cγ with Ryu et al.ʹs numerical data for polymer blends with various chain lengths. In addition, associated interactions between polymer segments are considered based on the secondary lattice concept. In comparison with experimental data, the calculated coexistence curves and critical points by the proposed model show better agreements than those of mDLM.