Theory of interchain packing and dynamics in associating copolymer liquids

We employ liquid state theory to explore the role of attractive groups regularly co-polymerized in a chain backbone on the structure and dynamics of unentangled polymer liquids that can form thermoreversible bonds. Significant progress has been made by others using coarse-grained polymer physics models based on phenomenological input parameters that quantify the sticker association energy and bond dissociation lifetime. However, these approaches are not force-based, and do not include molecular-scale information about packing correlations and its consequences on sticker clustering, dynamic bond formation and dissociation events. Based on the microscopic forces and single chain structure as input, we combine equilibrium integral equation theory and generalized Rouse models that capture local caging and physical bond formation to study the latter aspects and related issues such as emergent elasticity. The timescale for stickers and non-stickers that define the coupled activated bond breakage and local cage reorganization processes, and the correlation between structure and dynamics, are studied as a function of experimentally controllable variables such as polymer volume fraction, fraction of stickers, strength and spatial range of the attractive interaction, and chain length.