Computer simulation analysis of microstructure formation in monomer and polymer blends involving a glassy component

Monte Carlo and molecular dynamics simulations are performed for low‐molecular‐weight and polymeric A/B mixtures with a glassy component A. The possibility of a glass transition in the microregions enriched with A‐molecules is taken into account by introducing a “freezing constraint”. Two types of this constraint are considered in the present paper: either the diffusion motion of a given A‐particle is stopped if the concentration of A‐units in some sphere around a given particle is larger than a certain critical value (constraint of G‐type), or it is stopped if the concentration of “plasticizing” B‐molecules in this sphere is lower than a certain critical value (constraint of P‐type). It is shown that even for athermal A/B blends a “freezing constraint” of both types leads to the formation of well‐separated microsegregated clusters of glassy A‐units. The type of the final microstructure depends essentially on the type and the effective radius of the “freezing constraint”; both “frozen‐in” and equilibrium microdomain structures can emerge.