Thermodynamics of Polymer Blends: Generalized Double Lattice Model Thermodynamics of Polymer Blends: Generalized Double Lattice Model

Abstract

We generalize the modified double-lattice model (mDLM) to investigate the miscibility of polymer blend systems. We re-define model parameters as functions of chain length of polymer and interaction energy. The model parameters correct the degree of asymmetry between two molecules and reduce the mathematical defects originated from the truncation of higher order interaction energy terms. We correlate the model parameters with Ryu et al.’s simulation 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.