Miscibility behavior and single chain properties in polymer blends: a bond fluctuation model study

Computer simulation studies on the miscibility behavior and single chain properties in binary polymer blends are reviewed. We consider blends of various architectures in order to identify important architectural parameters on a coarse grained level and study their qualitative consequences for the miscibility behavior. The phase diagram, the relation between the exchange chemical potential and the composition, and the intermolecular paircorrelation functions for symmetric blends of linear chains, blends of cyclic polymers, blends with an asymmetry in cohesive energies, blends with different chain lengths, blends with distinct monomer shapes, and blends with a stiffness disparity between the components are discussed. We investiagte the temperature and composition dependence of the single chain conformations in symmetric and asymmetric blends and compare our findings to scaling arguments and detailed SCF calculations. Two aspects of the single chain dynamics in blends are discussed: the dynamics of short non--entangled chains in a binary blend and irreversible reactions of a small fraction of reactive polymers at a strongly segregated interface. Pertinent off-lattice simulations and analytical theories are briefly discussed.