(682i) Tuning Structure and Thermodynamics in Polymer Blends Containing Hydrogen Bonding Polymers: A Coarse-Grained Molecular Dynamics Simulation Study

In blends comprised of two homopolymer chemistries with hydrogen bonding (H-bonding) acceptor and donor functional groups, the H-bonding interactions lead to formation of supramolecular (co) polymers. The supramolecular (co) polymer architectures and resulting blend morphology (i.e., two-phase, disordered, lamellae, bicontinuous microemulsions) are a function of the number and placement of H-bonding groups in the homopolymer. In this talk, I will present a molecular dynamics (MD) simulation study using our recently developed coarse-grained (CG) model for polymers with directional interactions, to establish this phase behavior in homopolymer blends with varying number and placement of H-bonding groups along the polymer chains. I will share the validation of our CG MD simulation approach by comparing our results to the phase diagrams from past theoretical work of Fredrickson and coworkers for a symmetric blend of two types of end-associating polymers, one with H-bonding acceptor groups and one with donor groups, for varying H-bonding attraction strength and polymer segregation strength. Then, I will present CG MD simulation results in polymer blends with varying H-bonding groups composition (i.e., fraction of monomers with H-bonding groups along chains) 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 (e.g., two-phase, ordered/lamellar, and disordered, bicontinuous microemulsion), domain sizes, and fraction of associated H-bonding groups within the domains/interfaces as a function of H-bonding attraction strength and inherent polymer segregation strength.