(284g) Understanding the Interplay between Polymer Architecture and Solvent Quality through Coarse-Grained Molecular Dynamics Simulation and Liquid State Theory

Advances in polymer synthesis have made accessible a wide library of nonlinear polymer architectures, such as cyclic, star, bottlebrush, branched, and dendritic polymers. Due to entropic effects related to the interplay between the number of chain ends and branch points, polymer architecture can be used to tune key polymer melt and solution properties, including chain entanglement, segregation to surfaces, rheology, and self-assembly. As such, understanding and comparing the properties of polymers of varying architecture has been a topic of interest for many years. In this work, we apply explicit-solvent coarse-grained molecular dynamics (MD) simulations and Polymer Reference Interaction Site Model (PRISM) theory to understand how linear and cyclic polymers behave in solutions of varying solvent quality. We use the MD simulations to examine chain conformations and scaling behavior as a function of architecture and polymer-solvent interactions. We then apply the MD results within the framework of PRISM theory to calculate thermodynamic descriptors such as polymer-polymer second virial coefficients and effective polymer-solvent χ parameters. We find the scaling behavior and thermodynamics of linear and cyclic polymer solutions to be complex functions of architecture, solvent quality, and molecular weight, and we provide a mapping of the similarities and differences between linear and cyclic polymers in solutions of varying quality.