Comparison of a Born-Green-Yvon integral equation treatment of a compressible binary polymer blend on a lattice with recent simulations

Predictions of macroscopic and microscopic thermodynamic properties of a polymer blend using the Born–Green–Yvon (BGY) integral equation treatment of a compressible polymer mixture on a lattice are compared to recent simulations of compressible symmetric binary mixtures on a lattice. The theory is consistent with recent simulation studies which indicate that the critical temperature scales linearly with chain length. In addition, we show that the theory is effective in modeling the qualitative trends in the numbers of different types of pair contacts on the lattice, and also present comparisons of binodal and spinodal curves. These comparisons indicate that quantitative differences between the theory and simulation results are likely associated with the manner in which connectivity is treated in the lattice BGY description. We conclude by discussing avenues whereby connectivity may be incorporated more consistently in the development of the theory.