Coarse-grained molecular dynamics simulation study of structure and thermodynamics in blends with hydrogen bonding polymers*

Hydrogen bonding (H-bonding) in polymer blends can lead to the formation of supramolecular polymers whose morphology changes with the number and placement of H-bonding groups along the polymers. In this talk, we will present a molecular dynamics (MD) simulation study to understand morphology and phase behavior in blends with varying number and placement of H-bonding groups. We use our recently developed coarse-grained (CG) model for polymers with directional interactions and study a symmetric blend of two polymers, one with H-bonding acceptor groups and one with donor groups. First, we validate our MD simulation results against phase diagrams from past theoretical work of Fredrickson and coworkers on end associating polymers, for varying H-bonding attraction strength and polymer segregation strength. We then present results in polymer blends for varying H-bonding groups composition (i.e., fraction of monomers with H-bonding groups) and placement (e.g., random vs. regular placement of multiple H-bonding groups, center vs. end placement of a single H-bonding group per polymer). We characterize the blend morphology, domain sizes, and placement of H-bonding groups within the domains as a function of varying H-bonding attraction and polymer segregation strength.