Simulation and model development for the equation of state of heteronuclear non-additive copolymer chains

Molecular dynamics simulations of hard alternating copolymer chains compose d of size asymmetric nonadditive segments were performed. Different degrees of polymerization, densities, size ratios and nonadditivities were used. T he equation of state for these copolymers was investigated and models based on the first order thermodynamic perturbation theory (TPT1) and the polyme ric analog of the Percus-Yevick approximation (PPY) were developed to predi ct the compressibility factor:of the copolymers. The models predicted the c ompressibilities of the mixtures accurately at small size ratios, low degre es of polymerization and higher densities, The TPT1 model was generally mor e accurate in predicting: the compressibility factor than the PPY model.