A Molecular Dynamics Study on the Miscibility and Morphology of Polyester Blends used in Coil Coatings

Computational simulations can be used to save on both time and costs, complementing experimental work and providing further guidance. Immiscible polymer blends induce phase segregation, and in some cases can produce useful multicoat systems. This works uses a range of Molecular Dynamics Simulations methods, including an extended Flory Huggins Interaction Parameter χ to initially probe the interactions and miscibility between ester monomers commonly used in coil coatings. This work indicates that blends with similar backbone structures or “like with like” show increased miscibility and those with different structures lead to a large χ value and immiscibility. Further to this, polyester blends with different backbone structures have then been coarse grained with MARTINI beads and simulations of 10 µs have been run to identify the morphology of the blends at the mesoscopic level. Finally, the melamine crosslinker commonly used in polyester formulations has previously been shown to form agglomerates at higher melamine content, these agglomerates have been shown in atomistic simulations.