Impact of placement and composition of hydrogen bonding groups along polymer chains on blend morphology using coarse-grained molecular dynamics simulations*

In this talk, we will present our work involving molecular dynamics (MD) simulations and a recently developed coarse-grained (CG) model for polymers with directional interactions [Macromolecules (2019) 52 (7) 2725-2735] to predict polymer blends’ morphology for varying composition (i.e., fraction of monomers with H-bonding acceptor/donor groups along polymer chains) and placement of H-bonding acceptor/donor groups along polymer chains. We first validate our CGMD simulation approach by reproducing previously published theoretical phase diagrams for end-associating polymers at varying H-bonding strength vs. polymer segregation strength. We use the validated CGMD approach to elucidate how blends’ morphology varies with random and regular placement of multiple H-bonding groups along the polymer chains. For these varying placements of multiple H-bonding groups, we characterize the blend morphology (e.g., two-phase, lamellar, bicontinuous microemulsion, disordered and disordered microphase) and domain sizes as a function of varying H-bonding attraction vs. polymer segregation strength. Through the results from this study, we establish design rules for incorporating H-bonding functional groups along polymer chains to achieve precisely tuned blend morphology.